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diff --git a/doc/languages-frameworks/agda.section.md b/doc/languages-frameworks/agda.section.md new file mode 100644 index 00000000000..775a7a1a642 --- /dev/null +++ b/doc/languages-frameworks/agda.section.md @@ -0,0 +1,256 @@ +# Agda {#agda} + +## How to use Agda {#how-to-use-agda} + +Agda is available as the [agda](https://search.nixos.org/packages?channel=unstable&show=agda&from=0&size=30&sort=relevance&query=agda) +package. + +The `agda` package installs an Agda-wrapper, which calls `agda` with `--library-file` +set to a generated library-file within the nix store, this means your library-file in +`$HOME/.agda/libraries` will be ignored. By default the agda package installs Agda +with no libraries, i.e. the generated library-file is empty. To use Agda with libraries, +the `agda.withPackages` function can be used. This function either takes: + +* A list of packages, +* or a function which returns a list of packages when given the `agdaPackages` attribute set, +* or an attribute set containing a list of packages and a GHC derivation for compilation (see below). +* or an attribute set containing a function which returns a list of packages when given the `agdaPackages` attribute set and a GHC derivation for compilation (see below). + +For example, suppose we wanted a version of Agda which has access to the standard library. This can be obtained with the expressions: + +```nix +agda.withPackages [ agdaPackages.standard-library ] +``` + +or + +```nix +agda.withPackages (p: [ p.standard-library ]) +``` + +or can be called as in the [Compiling Agda](#compiling-agda) section. + +If you want to use a different version of a library (for instance a development version) +override the `src` attribute of the package to point to your local repository + +```nix +agda.withPackages (p: [ + (p.standard-library.overrideAttrs (oldAttrs: { + version = "local version"; + src = /path/to/local/repo/agda-stdlib; + })) +]) +``` + +You can also reference a GitHub repository + +```nix +agda.withPackages (p: [ + (p.standard-library.overrideAttrs (oldAttrs: { + version = "1.5"; + src = fetchFromGitHub { + repo = "agda-stdlib"; + owner = "agda"; + rev = "v1.5"; + sha256 = "16fcb7ssj6kj687a042afaa2gq48rc8abihpm14k684ncihb2k4w"; + }; + })) +]) +``` + +If you want to use a library not added to Nixpkgs, you can add a +dependency to a local library by calling `agdaPackages.mkDerivation`. + +```nix +agda.withPackages (p: [ + (p.mkDerivation { + pname = "your-agda-lib"; + version = "1.0.0"; + src = /path/to/your-agda-lib; + }) +]) +``` + +Again you can reference GitHub + +```nix +agda.withPackages (p: [ + (p.mkDerivation { + pname = "your-agda-lib"; + version = "1.0.0"; + src = fetchFromGitHub { + repo = "repo"; + owner = "owner"; + version = "..."; + rev = "..."; + sha256 = "..."; + }; + }) +]) +``` + +See [Building Agda Packages](#building-agda-packages) for more information on `mkDerivation`. + +Agda will not by default use these libraries. To tell Agda to use a library we have some options: + +* Call `agda` with the library flag: + ```ShellSession + $ agda -l standard-library -i . MyFile.agda + ``` +* Write a `my-library.agda-lib` file for the project you are working on which may look like: + ``` + name: my-library + include: . + depend: standard-library + ``` +* Create the file `~/.agda/defaults` and add any libraries you want to use by default. + +More information can be found in the [official Agda documentation on library management](https://agda.readthedocs.io/en/v2.6.1/tools/package-system.html). + +## Compiling Agda {#compiling-agda} + +Agda modules can be compiled using the GHC backend with the `--compile` flag. A version of `ghc` with `ieee754` is made available to the Agda program via the `--with-compiler` flag. +This can be overridden by a different version of `ghc` as follows: + +```nix +agda.withPackages { + pkgs = [ ... ]; + ghc = haskell.compiler.ghcHEAD; +} +``` + +## Writing Agda packages {#writing-agda-packages} + +To write a nix derivation for an Agda library, first check that the library has a `*.agda-lib` file. + +A derivation can then be written using `agdaPackages.mkDerivation`. This has similar arguments to `stdenv.mkDerivation` with the following additions: + +* `everythingFile` can be used to specify the location of the `Everything.agda` file, defaulting to `./Everything.agda`. If this file does not exist then either it should be patched in or the `buildPhase` should be overridden (see below). +* `libraryName` should be the name that appears in the `*.agda-lib` file, defaulting to `pname`. +* `libraryFile` should be the file name of the `*.agda-lib` file, defaulting to `${libraryName}.agda-lib`. + +Here is an example `default.nix` + +```nix +{ nixpkgs ? <nixpkgs> }: +with (import nixpkgs {}); +agdaPackages.mkDerivation { + version = "1.0"; + pname = "my-agda-lib"; + src = ./.; + buildInputs = [ + agdaPackages.standard-library + ]; +} +``` + +### Building Agda packages {#building-agda-packages} + +The default build phase for `agdaPackages.mkDerivation` simply runs `agda` on the `Everything.agda` file. +If something else is needed to build the package (e.g. `make`) then the `buildPhase` should be overridden. +Additionally, a `preBuild` or `configurePhase` can be used if there are steps that need to be done prior to checking the `Everything.agda` file. +`agda` and the Agda libraries contained in `buildInputs` are made available during the build phase. + +### Installing Agda packages {#installing-agda-packages} + +The default install phase copies Agda source files, Agda interface files (`*.agdai`) and `*.agda-lib` files to the output directory. +This can be overridden. + +By default, Agda sources are files ending on `.agda`, or literate Agda files ending on `.lagda`, `.lagda.tex`, `.lagda.org`, `.lagda.md`, `.lagda.rst`. The list of recognised Agda source extensions can be extended by setting the `extraExtensions` config variable. + +## Maintaining the Agda package set on Nixpkgs {#maintaining-the-agda-package-set-on-nixpkgs} + +We are aiming at providing all common Agda libraries as packages on `nixpkgs`, +and keeping them up to date. +Contributions and maintenance help is always appreciated, +but the maintenance effort is typically low since the Agda ecosystem is quite small. + +The `nixpkgs` Agda package set tries to take up a role similar to that of [Stackage](https://www.stackage.org/) in the Haskell world. +It is a curated set of libraries that: + +1. Always work together. +2. Are as up-to-date as possible. + +While the Haskell ecosystem is huge, and Stackage is highly automatised, +the Agda package set is small and can (still) be maintained by hand. + +### Adding Agda packages to Nixpkgs {#adding-agda-packages-to-nixpkgs} + +To add an Agda package to `nixpkgs`, the derivation should be written to `pkgs/development/libraries/agda/${library-name}/` and an entry should be added to `pkgs/top-level/agda-packages.nix`. Here it is called in a scope with access to all other Agda libraries, so the top line of the `default.nix` can look like: + +```nix +{ mkDerivation, standard-library, fetchFromGitHub }: +``` + +Note that the derivation function is called with `mkDerivation` set to `agdaPackages.mkDerivation`, therefore you +could use a similar set as in your `default.nix` from [Writing Agda Packages](#writing-agda-packages) with +`agdaPackages.mkDerivation` replaced with `mkDerivation`. + +Here is an example skeleton derivation for iowa-stdlib: + +```nix +mkDerivation { + version = "1.5.0"; + pname = "iowa-stdlib"; + + src = ... + + libraryFile = ""; + libraryName = "IAL-1.3"; + + buildPhase = '' + patchShebangs find-deps.sh + make + ''; +} +``` + +This library has a file called `.agda-lib`, and so we give an empty string to `libraryFile` as nothing precedes `.agda-lib` in the filename. This file contains `name: IAL-1.3`, and so we let `libraryName = "IAL-1.3"`. This library does not use an `Everything.agda` file and instead has a Makefile, so there is no need to set `everythingFile` and we set a custom `buildPhase`. + +When writing an Agda package it is essential to make sure that no `.agda-lib` file gets added to the store as a single file (for example by using `writeText`). This causes Agda to think that the nix store is a Agda library and it will attempt to write to it whenever it typechecks something. See [https://github.com/agda/agda/issues/4613](https://github.com/agda/agda/issues/4613). + +In the pull request adding this library, +you can test whether it builds correctly by writing in a comment: + +``` +@ofborg build agdaPackages.iowa-stdlib +``` + +### Maintaining Agda packages + +As mentioned before, the aim is to have a compatible, and up-to-date package set. +These two conditions sometimes exclude each other: +For example, if we update `agdaPackages.standard-library` because there was an upstream release, +this will typically break many reverse dependencies, +i.e. downstream Agda libraries that depend on the standard library. +In `nixpkgs` we are typically among the first to notice this, +since we have build tests in place to check this. + +In a pull request updating e.g. the standard library, you should write the following comment: + +``` +@ofborg build agdaPackages.standard-library.passthru.tests +``` + +This will build all reverse dependencies of the standard library, +for example `agdaPackages.agda-categories`, or `agdaPackages.generic`. + +In some cases it is useful to build _all_ Agda packages. +This can be done with the following Github comment: + +``` +@ofborg build agda.passthru.tests.allPackages +``` + +Sometimes, the builds of the reverse dependencies fail because they have not yet been updated and released. +You should drop the maintainers a quick issue notifying them of the breakage, +citing the build error (which you can get from the ofborg logs). +If you are motivated, you might even send a pull request that fixes it. +Usually, the maintainers will answer within a week or two with a new release. +Bumping the version of that reverse dependency should be a further commit on your PR. + +In the rare case that a new release is not to be expected within an acceptable time, +simply mark the broken package as broken by setting `meta.broken = true;`. +This will exclude it from the build test. +It can be added later when it is fixed, +and does not hinder the advancement of the whole package set in the meantime. diff --git a/doc/languages-frameworks/android.section.md b/doc/languages-frameworks/android.section.md new file mode 100644 index 00000000000..28128ead663 --- /dev/null +++ b/doc/languages-frameworks/android.section.md @@ -0,0 +1,346 @@ +# Android {#android} + +The Android build environment provides three major features and a number of +supporting features. + +## Deploying an Android SDK installation with plugins {#deploying-an-android-sdk-installation-with-plugins} + +The first use case is deploying the SDK with a desired set of plugins or subsets +of an SDK. + +```nix +with import <nixpkgs> {}; + +let + androidComposition = androidenv.composeAndroidPackages { + toolsVersion = "26.1.1"; + platformToolsVersion = "30.0.5"; + buildToolsVersions = [ "30.0.3" ]; + includeEmulator = false; + emulatorVersion = "30.3.4"; + platformVersions = [ "28" "29" "30" ]; + includeSources = false; + includeSystemImages = false; + systemImageTypes = [ "google_apis_playstore" ]; + abiVersions = [ "armeabi-v7a" "arm64-v8a" ]; + cmakeVersions = [ "3.10.2" ]; + includeNDK = true; + ndkVersions = ["22.0.7026061"]; + useGoogleAPIs = false; + useGoogleTVAddOns = false; + includeExtras = [ + "extras;google;gcm" + ]; + }; +in +androidComposition.androidsdk +``` + +The above function invocation states that we want an Android SDK with the above +specified plugin versions. By default, most plugins are disabled. Notable +exceptions are the tools, platform-tools and build-tools sub packages. + +The following parameters are supported: + +* `toolsVersion`, specifies the version of the tools package to use +* `platformsToolsVersion` specifies the version of the `platform-tools` plugin +* `buildToolsVersions` specifies the versions of the `build-tools` plugins to + use. +* `includeEmulator` specifies whether to deploy the emulator package (`false` + by default). When enabled, the version of the emulator to deploy can be + specified by setting the `emulatorVersion` parameter. +* `cmakeVersions` specifies which CMake versions should be deployed. +* `includeNDK` specifies that the Android NDK bundle should be included. + Defaults to: `false`. +* `ndkVersions` specifies the NDK versions that we want to use. These are linked + under the `ndk` directory of the SDK root, and the first is linked under the + `ndk-bundle` directory. +* `ndkVersion` is equivalent to specifying one entry in `ndkVersions`, and + `ndkVersions` overrides this parameter if provided. +* `includeExtras` is an array of identifier strings referring to arbitrary + add-on packages that should be installed. +* `platformVersions` specifies which platform SDK versions should be included. + +For each platform version that has been specified, we can apply the following +options: + +* `includeSystemImages` specifies whether a system image for each platform SDK + should be included. +* `includeSources` specifies whether the sources for each SDK version should be + included. +* `useGoogleAPIs` specifies that for each selected platform version the + Google API should be included. +* `useGoogleTVAddOns` specifies that for each selected platform version the + Google TV add-on should be included. + +For each requested system image we can specify the following options: + +* `systemImageTypes` specifies what kind of system images should be included. + Defaults to: `default`. +* `abiVersions` specifies what kind of ABI version of each system image should + be included. Defaults to: `armeabi-v7a`. + +Most of the function arguments have reasonable default settings. + +You can specify license names: + +* `extraLicenses` is a list of license names. + You can get these names from repo.json or `querypackages.sh licenses`. The SDK + license (`android-sdk-license`) is accepted for you if you set accept_license + to true. If you are doing something like working with preview SDKs, you will + want to add `android-sdk-preview-license` or whichever license applies here. + +Additionally, you can override the repositories that composeAndroidPackages will +pull from: + +* `repoJson` specifies a path to a generated repo.json file. You can generate this + by running `generate.sh`, which in turn will call into `mkrepo.rb`. +* `repoXmls` is an attribute set containing paths to repo XML files. If specified, + it takes priority over `repoJson`, and will trigger a local build writing out a + repo.json to the Nix store based on the given repository XMLs. + +```nix +repoXmls = { + packages = [ ./xml/repository2-1.xml ]; + images = [ + ./xml/android-sys-img2-1.xml + ./xml/android-tv-sys-img2-1.xml + ./xml/android-wear-sys-img2-1.xml + ./xml/android-wear-cn-sys-img2-1.xml + ./xml/google_apis-sys-img2-1.xml + ./xml/google_apis_playstore-sys-img2-1.xml + ]; + addons = [ ./xml/addon2-1.xml ]; +}; +``` + +When building the above expression with: + +```bash +$ nix-build +``` + +The Android SDK gets deployed with all desired plugin versions. + +We can also deploy subsets of the Android SDK. For example, to only the +`platform-tools` package, you can evaluate the following expression: + +```nix +with import <nixpkgs> {}; + +let + androidComposition = androidenv.composeAndroidPackages { + # ... + }; +in +androidComposition.platform-tools +``` + +## Using predefined Android package compositions {#using-predefined-android-package-compositions} + +In addition to composing an Android package set manually, it is also possible +to use a predefined composition that contains all basic packages for a specific +Android version, such as version 9.0 (API-level 28). + +The following Nix expression can be used to deploy the entire SDK with all basic +plugins: + +```nix +with import <nixpkgs> {}; + +androidenv.androidPkgs_9_0.androidsdk +``` + +It is also possible to use one plugin only: + +```nix +with import <nixpkgs> {}; + +androidenv.androidPkgs_9_0.platform-tools +``` + +## Building an Android application {#building-an-android-application} + +In addition to the SDK, it is also possible to build an Ant-based Android +project and automatically deploy all the Android plugins that a project +requires. + + +```nix +with import <nixpkgs> {}; + +androidenv.buildApp { + name = "MyAndroidApp"; + src = ./myappsources; + release = true; + + # If release is set to true, you need to specify the following parameters + keyStore = ./keystore; + keyAlias = "myfirstapp"; + keyStorePassword = "mykeystore"; + keyAliasPassword = "myfirstapp"; + + # Any Android SDK parameters that install all the relevant plugins that a + # build requires + platformVersions = [ "24" ]; + + # When we include the NDK, then ndk-build is invoked before Ant gets invoked + includeNDK = true; +} +``` + +Aside from the app-specific build parameters (`name`, `src`, `release` and +keystore parameters), the `buildApp {}` function supports all the function +parameters that the SDK composition function (the function shown in the +previous section) supports. + +This build function is particularly useful when it is desired to use +[Hydra](https://nixos.org/hydra): the Nix-based continuous integration solution +to build Android apps. An Android APK gets exposed as a build product and can be +installed on any Android device with a web browser by navigating to the build +result page. + +## Spawning emulator instances {#spawning-emulator-instances} + +For testing purposes, it can also be quite convenient to automatically generate +scripts that spawn emulator instances with all desired configuration settings. + +An emulator spawn script can be configured by invoking the `emulateApp {}` +function: + +```nix +with import <nixpkgs> {}; + +androidenv.emulateApp { + name = "emulate-MyAndroidApp"; + platformVersion = "28"; + abiVersion = "x86"; # armeabi-v7a, mips, x86_64 + systemImageType = "google_apis_playstore"; +} +``` + +Additional flags may be applied to the Android SDK's emulator through the runtime environment variable `$NIX_ANDROID_EMULATOR_FLAGS`. + +It is also possible to specify an APK to deploy inside the emulator +and the package and activity names to launch it: + +```nix +with import <nixpkgs> {}; + +androidenv.emulateApp { + name = "emulate-MyAndroidApp"; + platformVersion = "24"; + abiVersion = "armeabi-v7a"; # mips, x86, x86_64 + systemImageType = "default"; + useGoogleAPIs = false; + app = ./MyApp.apk; + package = "MyApp"; + activity = "MainActivity"; +} +``` + +In addition to prebuilt APKs, you can also bind the APK parameter to a +`buildApp {}` function invocation shown in the previous example. + +## Notes on environment variables in Android projects {#notes-on-environment-variables-in-android-projects} + +* `ANDROID_SDK_ROOT` should point to the Android SDK. In your Nix expressions, this should be + `${androidComposition.androidsdk}/libexec/android-sdk`. Note that `ANDROID_HOME` is deprecated, + but if you rely on tools that need it, you can export it too. +* `ANDROID_NDK_ROOT` should point to the Android NDK, if you're doing NDK development. + In your Nix expressions, this should be `${ANDROID_SDK_ROOT}/ndk-bundle`. + +If you are running the Android Gradle plugin, you need to export GRADLE_OPTS to override aapt2 +to point to the aapt2 binary in the Nix store as well, or use a FHS environment so the packaged +aapt2 can run. If you don't want to use a FHS environment, something like this should work: + +```nix +let + buildToolsVersion = "30.0.3"; + + # Use buildToolsVersion when you define androidComposition + androidComposition = <...>; +in +pkgs.mkShell rec { + ANDROID_SDK_ROOT = "${androidComposition.androidsdk}/libexec/android-sdk"; + ANDROID_NDK_ROOT = "${ANDROID_SDK_ROOT}/ndk-bundle"; + + # Use the same buildToolsVersion here + GRADLE_OPTS = "-Dorg.gradle.project.android.aapt2FromMavenOverride=${ANDROID_SDK_ROOT}/build-tools/${buildToolsVersion}/aapt2"; +} +``` + +If you are using cmake, you need to add it to PATH in a shell hook or FHS env profile. +The path is suffixed with a build number, but properly prefixed with the version. +So, something like this should suffice: + +```nix +let + cmakeVersion = "3.10.2"; + + # Use cmakeVersion when you define androidComposition + androidComposition = <...>; +in +pkgs.mkShell rec { + ANDROID_SDK_ROOT = "${androidComposition.androidsdk}/libexec/android-sdk"; + ANDROID_NDK_ROOT = "${ANDROID_SDK_ROOT}/ndk-bundle"; + + # Use the same cmakeVersion here + shellHook = '' + export PATH="$(echo "$ANDROID_SDK_ROOT/cmake/${cmakeVersion}".*/bin):$PATH" + ''; +} +``` + +Note that running Android Studio with ANDROID_SDK_ROOT set will automatically write a +`local.properties` file with `sdk.dir` set to $ANDROID_SDK_ROOT if one does not already +exist. If you are using the NDK as well, you may have to add `ndk.dir` to this file. + +An example shell.nix that does all this for you is provided in examples/shell.nix. +This shell.nix includes a shell hook that overwrites local.properties with the correct +sdk.dir and ndk.dir values. This will ensure that the SDK and NDK directories will +both be correct when you run Android Studio inside nix-shell. + +## Notes on improving build.gradle compatibility {#notes-on-improving-build.gradle-compatibility} + +Ensure that your buildToolsVersion and ndkVersion match what is declared in androidenv. +If you are using cmake, make sure its declared version is correct too. + +Otherwise, you may get cryptic errors from aapt2 and the Android Gradle plugin warning +that it cannot install the build tools because the SDK directory is not writeable. + +```gradle +android { + buildToolsVersion "30.0.3" + ndkVersion = "22.0.7026061" + externalNativeBuild { + cmake { + version "3.10.2" + } + } +} + +``` + +## Querying the available versions of each plugin {#querying-the-available-versions-of-each-plugin} + +repo.json provides all the options in one file now. + +A shell script in the `pkgs/development/mobile/androidenv/` subdirectory can be used to retrieve all +possible options: + +```bash +./querypackages.sh packages +``` + +The above command-line instruction queries all package versions in repo.json. + +## Updating the generated expressions {#updating-the-generated-expressions} + +repo.json is generated from XML files that the Android Studio package manager uses. +To update the expressions run the `generate.sh` script that is stored in the +`pkgs/development/mobile/androidenv/` subdirectory: + +```bash +./generate.sh +``` diff --git a/doc/languages-frameworks/beam.section.md b/doc/languages-frameworks/beam.section.md new file mode 100644 index 00000000000..f6c74cb01e4 --- /dev/null +++ b/doc/languages-frameworks/beam.section.md @@ -0,0 +1,373 @@ +# BEAM Languages (Erlang, Elixir & LFE) {#sec-beam} + +## Introduction {#beam-introduction} + +In this document and related Nix expressions, we use the term, _BEAM_, to describe the environment. BEAM is the name of the Erlang Virtual Machine and, as far as we're concerned, from a packaging perspective, all languages that run on the BEAM are interchangeable. That which varies, like the build system, is transparent to users of any given BEAM package, so we make no distinction. + +## Available versions and deprecations schedule {#available-versions-and-deprecations-schedule} + +### Elixir {#elixir} + +nixpkgs follows the [official elixir deprecation schedule](https://hexdocs.pm/elixir/compatibility-and-deprecations.html) and keeps the last 5 released versions of Elixir available. + +## Structure {#beam-structure} + +All BEAM-related expressions are available via the top-level `beam` attribute, which includes: + +- `interpreters`: a set of compilers running on the BEAM, including multiple Erlang/OTP versions (`beam.interpreters.erlangR22`, etc), Elixir (`beam.interpreters.elixir`) and LFE (Lisp Flavoured Erlang) (`beam.interpreters.lfe`). + +- `packages`: a set of package builders (Mix and rebar3), each compiled with a specific Erlang/OTP version, e.g. `beam.packages.erlang22`. + +The default Erlang compiler, defined by `beam.interpreters.erlang`, is aliased as `erlang`. The default BEAM package set is defined by `beam.packages.erlang` and aliased at the top level as `beamPackages`. + +To create a package builder built with a custom Erlang version, use the lambda, `beam.packagesWith`, which accepts an Erlang/OTP derivation and produces a package builder similar to `beam.packages.erlang`. + +Many Erlang/OTP distributions available in `beam.interpreters` have versions with ODBC and/or Java enabled or without wx (no observer support). For example, there's `beam.interpreters.erlangR22_odbc_javac`, which corresponds to `beam.interpreters.erlangR22` and `beam.interpreters.erlangR22_nox`, which corresponds to `beam.interpreters.erlangR22`. + +## Build Tools {#build-tools} + +### Rebar3 {#build-tools-rebar3} + +We provide a version of Rebar3, under `rebar3`. We also provide a helper to fetch Rebar3 dependencies from a lockfile under `fetchRebar3Deps`. + +We also provide a version on Rebar3 with plugins included, under `rebar3WithPlugins`. This package is a function which takes two arguments: `plugins`, a list of nix derivations to include as plugins (loaded only when specified in `rebar.config`), and `globalPlugins`, which should always be loaded by rebar3. Example: `rebar3WithPlugins { globalPlugins = [beamPackages.pc]; }`. + +When adding a new plugin it is important that the `packageName` attribute is the same as the atom used by rebar3 to refer to the plugin. + +### Mix & Erlang.mk {#build-tools-other} + +Erlang.mk works exactly as expected. There is a bootstrap process that needs to be run, which is supported by the `buildErlangMk` derivation. + +For Elixir applications use `mixRelease` to make a release. See examples for more details. + +There is also a `buildMix` helper, whose behavior is closer to that of `buildErlangMk` and `buildRebar3`. The primary difference is that mixRelease makes a release, while buildMix only builds the package, making it useful for libraries and other dependencies. + +## How to Install BEAM Packages {#how-to-install-beam-packages} + +BEAM builders are not registered at the top level, simply because they are not relevant to the vast majority of Nix users. To install any of those builders into your profile, refer to them by their attribute path `beamPackages.rebar3`: + +```ShellSession +$ nix-env -f "<nixpkgs>" -iA beamPackages.rebar3 +``` + +## Packaging BEAM Applications {#packaging-beam-applications} + +### Erlang Applications {#packaging-erlang-applications} + +#### Rebar3 Packages {#rebar3-packages} + +The Nix function, `buildRebar3`, defined in `beam.packages.erlang.buildRebar3` and aliased at the top level, can be used to build a derivation that understands how to build a Rebar3 project. + +If a package needs to compile native code via Rebar3's port compilation mechanism, add `compilePort = true;` to the derivation. + +#### Erlang.mk Packages {#erlang-mk-packages} + +Erlang.mk functions similarly to Rebar3, except we use `buildErlangMk` instead of `buildRebar3`. + +#### Mix Packages {#mix-packages} + +`mixRelease` is used to make a release in the mix sense. Dependencies will need to be fetched with `fetchMixDeps` and passed to it. + +#### mixRelease - Elixir Phoenix example {#mix-release-elixir-phoenix-example} + +there are 3 steps, frontend dependencies (javascript), backend dependencies (elixir) and the final derivation that puts both of those together + +##### mixRelease - Frontend dependencies (javascript) {#mix-release-javascript-deps} + +For phoenix projects, inside of nixpkgs you can either use yarn2nix (mkYarnModule) or node2nix. An example with yarn2nix can be found [here](https://github.com/NixOS/nixpkgs/blob/master/pkgs/servers/web-apps/plausible/default.nix#L39). An example with node2nix will follow. To package something outside of nixpkgs, you have alternatives like [npmlock2nix](https://github.com/nix-community/npmlock2nix) or [nix-npm-buildpackage](https://github.com/serokell/nix-npm-buildpackage) + +##### mixRelease - backend dependencies (mix) {#mix-release-mix-deps} + +There are 2 ways to package backend dependencies. With mix2nix and with a fixed-output-derivation (FOD). + +###### mix2nix {#mix2nix} + +`mix2nix` is a cli tool available in nixpkgs. it will generate a nix expression from a mix.lock file. It is quite standard in the 2nix tool series. + +Note that currently mix2nix can't handle git dependencies inside the mix.lock file. If you have git dependencies, you can either add them manually (see [example](https://github.com/NixOS/nixpkgs/blob/master/pkgs/servers/pleroma/default.nix#L20)) or use the FOD method. + +The advantage of using mix2nix is that nix will know your whole dependency graph. On a dependency update, this won't trigger a full rebuild and download of all the dependencies, where FOD will do so. + +Practical steps: + +- run `mix2nix > mix_deps.nix` in the upstream repo. +- pass `mixNixDeps = with pkgs; import ./mix_deps.nix { inherit lib beamPackages; };` as an argument to mixRelease. + +If there are git depencencies. + +- You'll need to fix the version artificially in mix.exs and regenerate the mix.lock with fixed version (on upstream). This will enable you to run `mix2nix > mix_deps.nix`. +- From the mix_deps.nix file, remove the dependencies that had git versions and pass them as an override to the import function. + +```nix + mixNixDeps = import ./mix.nix { + inherit beamPackages lib; + overrides = (final: prev: { + # mix2nix does not support git dependencies yet, + # so we need to add them manually + prometheus_ex = beamPackages.buildMix rec { + name = "prometheus_ex"; + version = "3.0.5"; + + # Change the argument src with the git src that you actually need + src = fetchFromGitLab { + domain = "git.pleroma.social"; + group = "pleroma"; + owner = "elixir-libraries"; + repo = "prometheus.ex"; + rev = "a4e9beb3c1c479d14b352fd9d6dd7b1f6d7deee5"; + sha256 = "1v0q4bi7sb253i8q016l7gwlv5562wk5zy3l2sa446csvsacnpjk"; + }; + # you can re-use the same beamDeps argument as generated + beamDeps = with final; [ prometheus ]; + }; + }); +}; +``` + +You will need to run the build process once to fix the sha256 to correspond to your new git src. + +###### FOD {#fixed-output-derivation} + +A fixed output derivation will download mix dependencies from the internet. To ensure reproducibility, a hash will be supplied. Note that mix is relatively reproducible. An FOD generating a different hash on each run hasn't been observed (as opposed to npm where the chances are relatively high). See [elixir_ls](https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/beam-modules/elixir_ls.nix) for a usage example of FOD. + +Practical steps + +- start with the following argument to mixRelease + +```nix + mixFodDeps = fetchMixDeps { + pname = "mix-deps-${pname}"; + inherit src version; + sha256 = lib.fakeSha256; + }; +``` + +The first build will complain about the sha256 value, you can replace with the suggested value after that. + +Note that if after you've replaced the value, nix suggests another sha256, then mix is not fetching the dependencies reproducibly. An FOD will not work in that case and you will have to use mix2nix. + +##### mixRelease - example {#mix-release-example} + +Here is how your `default.nix` file would look for a phoenix project. + +```nix +with import <nixpkgs> { }; + +let + # beam.interpreters.erlangR23 is available if you need a particular version + packages = beam.packagesWith beam.interpreters.erlang; + + pname = "your_project"; + version = "0.0.1"; + + src = builtins.fetchgit { + url = "ssh://git@github.com/your_id/your_repo"; + rev = "replace_with_your_commit"; + }; + + # if using mix2nix you can use the mixNixDeps attribute + mixFodDeps = packages.fetchMixDeps { + pname = "mix-deps-${pname}"; + inherit src version; + # nix will complain and tell you the right value to replace this with + sha256 = lib.fakeSha256; + # if you have build time environment variables add them here + MY_ENV_VAR="my_value"; + }; + + nodeDependencies = (pkgs.callPackage ./assets/default.nix { }).shell.nodeDependencies; + +in packages.mixRelease { + inherit src pname version mixFodDeps; + # if you have build time environment variables add them here + MY_ENV_VAR="my_value"; + + postBuild = '' + ln -sf ${nodeDependencies}/lib/node_modules assets/node_modules + npm run deploy --prefix ./assets + + # for external task you need a workaround for the no deps check flag + # https://github.com/phoenixframework/phoenix/issues/2690 + mix do deps.loadpaths --no-deps-check, phx.digest + mix phx.digest --no-deps-check + ''; +} +``` + +Setup will require the following steps: + +- Move your secrets to runtime environment variables. For more information refer to the [runtime.exs docs](https://hexdocs.pm/mix/Mix.Tasks.Release.html#module-runtime-configuration). On a fresh Phoenix build that would mean that both `DATABASE_URL` and `SECRET_KEY` need to be moved to `runtime.exs`. +- `cd assets` and `nix-shell -p node2nix --run node2nix --development` will generate a Nix expression containing your frontend dependencies +- commit and push those changes +- you can now `nix-build .` +- To run the release, set the `RELEASE_TMP` environment variable to a directory that your program has write access to. It will be used to store the BEAM settings. + +#### Example of creating a service for an Elixir - Phoenix project {#example-of-creating-a-service-for-an-elixir---phoenix-project} + +In order to create a service with your release, you could add a `service.nix` +in your project with the following + +```nix +{config, pkgs, lib, ...}: + +let + release = pkgs.callPackage ./default.nix; + release_name = "app"; + working_directory = "/home/app"; +in +{ + systemd.services.${release_name} = { + wantedBy = [ "multi-user.target" ]; + after = [ "network.target" "postgresql.service" ]; + # note that if you are connecting to a postgres instance on a different host + # postgresql.service should not be included in the requires. + requires = [ "network-online.target" "postgresql.service" ]; + description = "my app"; + environment = { + # RELEASE_TMP is used to write the state of the + # VM configuration when the system is running + # it needs to be a writable directory + RELEASE_TMP = working_directory; + # can be generated in an elixir console with + # Base.encode32(:crypto.strong_rand_bytes(32)) + RELEASE_COOKIE = "my_cookie"; + MY_VAR = "my_var"; + }; + serviceConfig = { + Type = "exec"; + DynamicUser = true; + WorkingDirectory = working_directory; + # Implied by DynamicUser, but just to emphasize due to RELEASE_TMP + PrivateTmp = true; + ExecStart = '' + ${release}/bin/${release_name} start + ''; + ExecStop = '' + ${release}/bin/${release_name} stop + ''; + ExecReload = '' + ${release}/bin/${release_name} restart + ''; + Restart = "on-failure"; + RestartSec = 5; + StartLimitBurst = 3; + StartLimitInterval = 10; + }; + # disksup requires bash + path = [ pkgs.bash ]; + }; + + # in case you have migration scripts or you want to use a remote shell + environment.systemPackages = [ release ]; +} +``` + +## How to Develop {#how-to-develop} + +### Creating a Shell {#creating-a-shell} + +Usually, we need to create a `shell.nix` file and do our development inside of the environment specified therein. Just install your version of Erlang and any other interpreters, and then use your normal build tools. As an example with Elixir: + +```nix +{ pkgs ? import <nixpkgs> {} }: + +with pkgs; +let + elixir = beam.packages.erlangR24.elixir_1_12; +in +mkShell { + buildInputs = [ elixir ]; +} +``` + +### Using an overlay + +If you need to use an overlay to change some attributes of a derivation, e.g. if you need a bugfix from a version that is not yet available in nixpkgs, you can override attributes such as `version` (and the corresponding `sha256`) and then use this overlay in your development environment: + +#### `shell.nix` + +```nix +let + elixir_1_13_1_overlay = (self: super: { + elixir_1_13 = super.elixir_1_13.override { + version = "1.13.1"; + sha256 = "0z0b1w2vvw4vsnb99779c2jgn9bgslg7b1pmd9vlbv02nza9qj5p"; + }; + }); + pkgs = import <nixpkgs> { overlays = [ elixir_1_13_1_overlay ]; }; +in +with pkgs; +mkShell { + buildInputs = [ + elixir_1_13 + ]; +} +``` + +#### Elixir - Phoenix project {#elixir---phoenix-project} + +Here is an example `shell.nix`. + +```nix +with import <nixpkgs> { }; + +let + # define packages to install + basePackages = [ + git + # replace with beam.packages.erlang.elixir_1_13 if you need + beam.packages.erlang.elixir + nodejs + postgresql_14 + # only used for frontend dependencies + # you are free to use yarn2nix as well + nodePackages.node2nix + # formatting js file + nodePackages.prettier + ]; + + inputs = basePackages ++ lib.optionals stdenv.isLinux [ inotify-tools ] + ++ lib.optionals stdenv.isDarwin + (with darwin.apple_sdk.frameworks; [ CoreFoundation CoreServices ]); + + # define shell startup command + hooks = '' + # this allows mix to work on the local directory + mkdir -p .nix-mix .nix-hex + export MIX_HOME=$PWD/.nix-mix + export HEX_HOME=$PWD/.nix-mix + # make hex from Nixpkgs available + # `mix local.hex` will install hex into MIX_HOME and should take precedence + export MIX_PATH="${beam.packages.erlang.hex}/lib/erlang/lib/hex/ebin" + export PATH=$MIX_HOME/bin:$HEX_HOME/bin:$PATH + export LANG=C.UTF-8 + # keep your shell history in iex + export ERL_AFLAGS="-kernel shell_history enabled" + + # postges related + # keep all your db data in a folder inside the project + export PGDATA="$PWD/db" + + # phoenix related env vars + export POOL_SIZE=15 + export DB_URL="postgresql://postgres:postgres@localhost:5432/db" + export PORT=4000 + export MIX_ENV=dev + # add your project env vars here, word readable in the nix store. + export ENV_VAR="your_env_var" + ''; + +in mkShell { + buildInputs = inputs; + shellHook = hooks; +} +``` + +Initializing the project will require the following steps: + +- create the db directory `initdb ./db` (inside your mix project folder) +- create the postgres user `createuser postgres -ds` +- create the db `createdb db` +- start the postgres instance `pg_ctl -l "$PGDATA/server.log" start` +- add the `/db` folder to your `.gitignore` +- you can start your phoenix server and get a shell with `iex -S mix phx.server` diff --git a/doc/languages-frameworks/bower.section.md b/doc/languages-frameworks/bower.section.md new file mode 100644 index 00000000000..6226dc0702d --- /dev/null +++ b/doc/languages-frameworks/bower.section.md @@ -0,0 +1,158 @@ +# Bower {#sec-bower} + +[Bower](https://bower.io) is a package manager for web site front-end components. Bower packages (comprising of build artefacts and sometimes sources) are stored in `git` repositories, typically on Github. The package registry is run by the Bower team with package metadata coming from the `bower.json` file within each package. + +The end result of running Bower is a `bower_components` directory which can be included in the web app's build process. + +Bower can be run interactively, by installing `nodePackages.bower`. More interestingly, the Bower components can be declared in a Nix derivation, with the help of `nodePackages.bower2nix`. + +## bower2nix usage {#ssec-bower2nix-usage} + +Suppose you have a `bower.json` with the following contents: + +### Example bower.json {#ex-bowerJson} + +```json + "name": "my-web-app", + "dependencies": { + "angular": "~1.5.0", + "bootstrap": "~3.3.6" + } +``` + +Running `bower2nix` will produce something like the following output: + +```nix +{ fetchbower, buildEnv }: +buildEnv { name = "bower-env"; ignoreCollisions = true; paths = [ + (fetchbower "angular" "1.5.3" "~1.5.0" "1749xb0firxdra4rzadm4q9x90v6pzkbd7xmcyjk6qfza09ykk9y") + (fetchbower "bootstrap" "3.3.6" "~3.3.6" "1vvqlpbfcy0k5pncfjaiskj3y6scwifxygfqnw393sjfxiviwmbv") + (fetchbower "jquery" "2.2.2" "1.9.1 - 2" "10sp5h98sqwk90y4k6hbdviwqzvzwqf47r3r51pakch5ii2y7js1") +]; +``` + +Using the `bower2nix` command line arguments, the output can be redirected to a file. A name like `bower-packages.nix` would be fine. + +The resulting derivation is a union of all the downloaded Bower packages (and their dependencies). To use it, they still need to be linked together by Bower, which is where `buildBowerComponents` is useful. + +## buildBowerComponents function {#ssec-build-bower-components} + +The function is implemented in [pkgs/development/bower-modules/generic/default.nix](https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/bower-modules/generic/default.nix). + +### Example buildBowerComponents {#ex-buildBowerComponents} + +```{=docbook} +<programlisting language="nix"> +bowerComponents = buildBowerComponents { + name = "my-web-app"; + generated = ./bower-packages.nix; <co xml:id="ex-buildBowerComponents-1" /> + src = myWebApp; <co xml:id="ex-buildBowerComponents-2" /> +}; +</programlisting> +``` + +In ["buildBowerComponents" example](#ex-buildBowerComponents) the following arguments are of special significance to the function: + +```{=docbook} +<calloutlist> + <callout arearefs="ex-buildBowerComponents-1"> + <para> + <varname>generated</varname> specifies the file which was created by <command>bower2nix</command>. + </para> + </callout> + <callout arearefs="ex-buildBowerComponents-2"> + <para> + <varname>src</varname> is your project's sources. It needs to contain a <filename>bower.json</filename> file. + </para> + </callout> +</calloutlist> +``` + +`buildBowerComponents` will run Bower to link together the output of `bower2nix`, resulting in a `bower_components` directory which can be used. + +Here is an example of a web frontend build process using `gulp`. You might use `grunt`, or anything else. + +### Example build script (gulpfile.js) {#ex-bowerGulpFile} + +```javascript +var gulp = require('gulp'); + +gulp.task('default', [], function () { + gulp.start('build'); +}); + +gulp.task('build', [], function () { + console.log("Just a dummy gulp build"); + gulp + .src(["./bower_components/**/*"]) + .pipe(gulp.dest("./gulpdist/")); +}); +``` + +### Example Full example — default.nix {#ex-buildBowerComponentsDefaultNix} + +```{=docbook} +<programlisting language="nix"> +{ myWebApp ? { outPath = ./.; name = "myWebApp"; } +, pkgs ? import <nixpkgs> {} +}: + +pkgs.stdenv.mkDerivation { + name = "my-web-app-frontend"; + src = myWebApp; + + buildInputs = [ pkgs.nodePackages.gulp ]; + + bowerComponents = pkgs.buildBowerComponents { <co xml:id="ex-buildBowerComponentsDefault-1" /> + name = "my-web-app"; + generated = ./bower-packages.nix; + src = myWebApp; + }; + + buildPhase = '' + cp --reflink=auto --no-preserve=mode -R $bowerComponents/bower_components . <co xml:id="ex-buildBowerComponentsDefault-2" /> + export HOME=$PWD <co xml:id="ex-buildBowerComponentsDefault-3" /> + ${pkgs.nodePackages.gulp}/bin/gulp build <co xml:id="ex-buildBowerComponentsDefault-4" /> + ''; + + installPhase = "mv gulpdist $out"; +} +</programlisting> +``` + +A few notes about [Full example — `default.nix`](#ex-buildBowerComponentsDefaultNix): + +```{=docbook} +<calloutlist> + <callout arearefs="ex-buildBowerComponentsDefault-1"> + <para> + The result of <varname>buildBowerComponents</varname> is an input to the frontend build. + </para> + </callout> + <callout arearefs="ex-buildBowerComponentsDefault-2"> + <para> + Whether to symlink or copy the <filename>bower_components</filename> directory depends on the build tool in use. In this case a copy is used to avoid <command>gulp</command> silliness with permissions. + </para> + </callout> + <callout arearefs="ex-buildBowerComponentsDefault-3"> + <para> + <command>gulp</command> requires <varname>HOME</varname> to refer to a writeable directory. + </para> + </callout> + <callout arearefs="ex-buildBowerComponentsDefault-4"> + <para> + The actual build command. Other tools could be used. + </para> + </callout> +</calloutlist> +``` + +## Troubleshooting {#ssec-bower2nix-troubleshooting} + +### ENOCACHE errors from buildBowerComponents {#enocache-errors-from-buildbowercomponents} + +This means that Bower was looking for a package version which doesn't exist in the generated `bower-packages.nix`. + +If `bower.json` has been updated, then run `bower2nix` again. + +It could also be a bug in `bower2nix` or `fetchbower`. If possible, try reformulating the version specification in `bower.json`. diff --git a/doc/languages-frameworks/coq.section.md b/doc/languages-frameworks/coq.section.md new file mode 100644 index 00000000000..9a692104a04 --- /dev/null +++ b/doc/languages-frameworks/coq.section.md @@ -0,0 +1,83 @@ +# Coq and coq packages {#sec-language-coq} + +## Coq derivation: `coq` {#coq-derivation-coq} + +The Coq derivation is overridable through the `coq.override overrides`, where overrides is an attribute set which contains the arguments to override. We recommend overriding either of the following + +* `version` (optional, defaults to the latest version of Coq selected for nixpkgs, see `pkgs/top-level/coq-packages` to witness this choice), which follows the conventions explained in the `coqPackages` section below, +* `customOCamlPackage` (optional, defaults to `null`, which lets Coq choose a version automatically), which can be set to any of the ocaml packages attribute of `ocaml-ng` (such as `ocaml-ng.ocamlPackages_4_10` which is the default for Coq 8.11 for example). +* `coq-version` (optional, defaults to the short version e.g. "8.10"), is a version number of the form "x.y" that indicates which Coq's version build behavior to mimic when using a source which is not a release. E.g. `coq.override { version = "d370a9d1328a4e1cdb9d02ee032f605a9d94ec7a"; coq-version = "8.10"; }`. + +## Coq packages attribute sets: `coqPackages` {#coq-packages-attribute-sets-coqpackages} + +The recommended way of defining a derivation for a Coq library, is to use the `coqPackages.mkCoqDerivation` function, which is essentially a specialization of `mkDerivation` taking into account most of the specifics of Coq libraries. The following attributes are supported: + +* `pname` (required) is the name of the package, +* `version` (optional, defaults to `null`), is the version to fetch and build, + this attribute is interpreted in several ways depending on its type and pattern: + * if it is a known released version string, i.e. from the `release` attribute below, the according release is picked, and the `version` attribute of the resulting derivation is set to this release string, + * if it is a majorMinor `"x.y"` prefix of a known released version (as defined above), then the latest `"x.y.z"` known released version is selected (for the ordering given by `versionAtLeast`), + * if it is a path or a string representing an absolute path (i.e. starting with `"/"`), the provided path is selected as a source, and the `version` attribute of the resulting derivation is set to `"dev"`, + * if it is a string of the form `owner:branch` then it tries to download the `branch` of owner `owner` for a project of the same name using the same vcs, and the `version` attribute of the resulting derivation is set to `"dev"`, additionally if the owner is not provided (i.e. if the `owner:` prefix is missing), it defaults to the original owner of the package (see below), + * if it is a string of the form `"#N"`, and the domain is github, then it tries to download the current head of the pull request `#N` from github, +* `defaultVersion` (optional). Coq libraries may be compatible with some specific versions of Coq only. The `defaultVersion` attribute is used when no `version` is provided (or if `version = null`) to select the version of the library to use by default, depending on the context. This selection will mainly depend on a `coq` version number but also possibly on other packages versions (e.g. `mathcomp`). If its value ends up to be `null`, the package is marked for removal in end-user `coqPackages` attribute set. +* `release` (optional, defaults to `{}`), lists all the known releases of the library and for each of them provides an attribute set with at least a `sha256` attribute (you may put the empty string `""` in order to automatically insert a fake sha256, this will trigger an error which will allow you to find the correct sha256), each attribute set of the list of releases also takes optional overloading arguments for the fetcher as below (i.e.`domain`, `owner`, `repo`, `rev` assuming the default fetcher is used) and optional overrides for the result of the fetcher (i.e. `version` and `src`). +* `fetcher` (optional, defaults to a generic fetching mechanism supporting github or gitlab based infrastructures), is a function that takes at least an `owner`, a `repo`, a `rev`, and a `sha256` and returns an attribute set with a `version` and `src`. +* `repo` (optional, defaults to the value of `pname`), +* `owner` (optional, defaults to `"coq-community"`). +* `domain` (optional, defaults to `"github.com"`), domains including the strings `"github"` or `"gitlab"` in their names are automatically supported, otherwise, one must change the `fetcher` argument to support them (cf `pkgs/development/coq-modules/heq/default.nix` for an example), +* `releaseRev` (optional, defaults to `(v: v)`), provides a default mapping from release names to revision hashes/branch names/tags, +* `displayVersion` (optional), provides a way to alter the computation of `name` from `pname`, by explaining how to display version numbers, +* `namePrefix` (optional, defaults to `[ "coq" ]`), provides a way to alter the computation of `name` from `pname`, by explaining which dependencies must occur in `name`, +* `extraNativeBuildInputs` (optional), by default `nativeBuildInputs` just contains `coq`, this allows to add more native build inputs, `nativeBuildInputs` are executables and `buildInputs` are libraries and dependencies, +* `extraBuildInputs` (optional), this allows to add more build inputs, +* `mlPlugin` (optional, defaults to `false`). Some extensions (plugins) might require OCaml and sometimes other OCaml packages. Standard dependencies can be added by setting the current option to `true`. For a finer grain control, the `coq.ocamlPackages` attribute can be used in `extraBuildInputs` to depend on the same package set Coq was built against. +* `useDune2ifVersion` (optional, default to `(x: false)` uses Dune2 to build the package if the provided predicate evaluates to true on the version, e.g. `useDune2if = versions.isGe "1.1"` will use dune if the version of the package is greater or equal to `"1.1"`, +* `useDune2` (optional, defaults to `false`) uses Dune2 to build the package if set to true, the presence of this attribute overrides the behavior of the previous one. +* `opam-name` (optional, defaults to concatenating with a dash separator the components of `namePrefix` and `pname`), name of the Dune package to build. +* `enableParallelBuilding` (optional, defaults to `true`), since it is activated by default, we provide a way to disable it. +* `extraInstallFlags` (optional), allows to extend `installFlags` which initializes the variable `COQMF_COQLIB` so as to install in the proper subdirectory. Indeed Coq libraries should be installed in `$(out)/lib/coq/${coq.coq-version}/user-contrib/`. Such directories are automatically added to the `$COQPATH` environment variable by the hook defined in the Coq derivation. +* `setCOQBIN` (optional, defaults to `true`), by default, the environment variable `$COQBIN` is set to the current Coq's binary, but one can disable this behavior by setting it to `false`, +* `useMelquiondRemake` (optional, default to `null`) is an attribute set, which, if given, overloads the `preConfigurePhases`, `configureFlags`, `buildPhase`, and `installPhase` attributes of the derivation for a specific use in libraries using `remake` as set up by Guillaume Melquiond for `flocq`, `gappalib`, `interval`, and `coquelicot` (see the corresponding derivation for concrete examples of use of this option). For backward compatibility, the attribute `useMelquiondRemake.logpath` must be set to the logical root of the library (otherwise, one can pass `useMelquiondRemake = {}` to activate this without backward compatibility). +* `dropAttrs`, `keepAttrs`, `dropDerivationAttrs` are all optional and allow to tune which attribute is added or removed from the final call to `mkDerivation`. + +It also takes other standard `mkDerivation` attributes, they are added as such, except for `meta` which extends an automatically computed `meta` (where the `platform` is the same as `coq` and the homepage is automatically computed). + +Here is a simple package example. It is a pure Coq library, thus it depends on Coq. It builds on the Mathematical Components library, thus it also takes some `mathcomp` derivations as `extraBuildInputs`. + +```nix +{ lib, mkCoqDerivation, version ? null +, coq, mathcomp, mathcomp-finmap, mathcomp-bigenough }: +with lib; mkCoqDerivation { + /* namePrefix leads to e.g. `name = coq8.11-mathcomp1.11-multinomials-1.5.2` */ + namePrefix = [ "coq" "mathcomp" ]; + pname = "multinomials"; + owner = "math-comp"; + inherit version; + defaultVersion = with versions; switch [ coq.version mathcomp.version ] [ + { cases = [ (range "8.7" "8.12") "1.11.0" ]; out = "1.5.2"; } + { cases = [ (range "8.7" "8.11") (range "1.8" "1.10") ]; out = "1.5.0"; } + { cases = [ (range "8.7" "8.10") (range "1.8" "1.10") ]; out = "1.4"; } + { cases = [ "8.6" (range "1.6" "1.7") ]; out = "1.1"; } + ] null; + release = { + "1.5.2".sha256 = "15aspf3jfykp1xgsxf8knqkxv8aav2p39c2fyirw7pwsfbsv2c4s"; + "1.5.1".sha256 = "13nlfm2wqripaq671gakz5mn4r0xwm0646araxv0nh455p9ndjs3"; + "1.5.0".sha256 = "064rvc0x5g7y1a0nip6ic91vzmq52alf6in2bc2dmss6dmzv90hw"; + "1.5.0".rev = "1.5"; + "1.4".sha256 = "0vnkirs8iqsv8s59yx1fvg1nkwnzydl42z3scya1xp1b48qkgn0p"; + "1.3".sha256 = "0l3vi5n094nx3qmy66hsv867fnqm196r8v605kpk24gl0aa57wh4"; + "1.2".sha256 = "1mh1w339dslgv4f810xr1b8v2w7rpx6fgk9pz96q0fyq49fw2xcq"; + "1.1".sha256 = "1q8alsm89wkc0lhcvxlyn0pd8rbl2nnxg81zyrabpz610qqjqc3s"; + "1.0".sha256 = "1qmbxp1h81cy3imh627pznmng0kvv37k4hrwi2faa101s6bcx55m"; + }; + + propagatedBuildInputs = + [ mathcomp.ssreflect mathcomp.algebra mathcomp-finmap mathcomp-bigenough ]; + + meta = { + description = "A Coq/SSReflect Library for Monoidal Rings and Multinomials"; + license = licenses.cecill-c; + }; +} +``` diff --git a/doc/languages-frameworks/crystal.section.md b/doc/languages-frameworks/crystal.section.md new file mode 100644 index 00000000000..cbabba24f0c --- /dev/null +++ b/doc/languages-frameworks/crystal.section.md @@ -0,0 +1,73 @@ +# Crystal {#crystal} + +## Building a Crystal package {#building-a-crystal-package} + +This section uses [Mint](https://github.com/mint-lang/mint) as an example for how to build a Crystal package. + +If the Crystal project has any dependencies, the first step is to get a `shards.nix` file encoding those. Get a copy of the project and go to its root directory such that its `shard.lock` file is in the current directory. Executable projects should usually commit the `shard.lock` file, but sometimes that's not the case, which means you need to generate it yourself. With an existing `shard.lock` file, `crystal2nix` can be run. +```bash +$ git clone https://github.com/mint-lang/mint +$ cd mint +$ git checkout 0.5.0 +$ if [ ! -f shard.lock ]; then nix-shell -p shards --run "shards lock"; fi +$ nix-shell -p crystal2nix --run crystal2nix +``` + +This should have generated a `shards.nix` file. + +Next create a Nix file for your derivation and use `pkgs.crystal.buildCrystalPackage` as follows: + +```nix +with import <nixpkgs> {}; +crystal.buildCrystalPackage rec { + pname = "mint"; + version = "0.5.0"; + + src = fetchFromGitHub { + owner = "mint-lang"; + repo = "mint"; + rev = version; + sha256 = "0vxbx38c390rd2ysvbwgh89v2232sh5rbsp3nk9wzb70jybpslvl"; + }; + + # Insert the path to your shards.nix file here + shardsFile = ./shards.nix; + + ... +} +``` + +This won't build anything yet, because we haven't told it what files build. We can specify a mapping from binary names to source files with the `crystalBinaries` attribute. The project's compilation instructions should show this. For Mint, the binary is called "mint", which is compiled from the source file `src/mint.cr`, so we'll specify this as follows: + +```nix + crystalBinaries.mint.src = "src/mint.cr"; + + # ... +``` + +Additionally you can override the default `crystal build` options (which are currently `--release --progress --no-debug --verbose`) with + +```nix + crystalBinaries.mint.options = [ "--release" "--verbose" ]; +``` + +Depending on the project, you might need additional steps to get it to compile successfully. In Mint's case, we need to link against openssl, so in the end the Nix file looks as follows: + +```nix +with import <nixpkgs> {}; +crystal.buildCrystalPackage rec { + version = "0.5.0"; + pname = "mint"; + src = fetchFromGitHub { + owner = "mint-lang"; + repo = "mint"; + rev = version; + sha256 = "0vxbx38c390rd2ysvbwgh89v2232sh5rbsp3nk9wzb70jybpslvl"; + }; + + shardsFile = ./shards.nix; + crystalBinaries.mint.src = "src/mint.cr"; + + buildInputs = [ openssl ]; +} +``` diff --git a/doc/languages-frameworks/dhall.section.md b/doc/languages-frameworks/dhall.section.md new file mode 100644 index 00000000000..4b49908b0b0 --- /dev/null +++ b/doc/languages-frameworks/dhall.section.md @@ -0,0 +1,463 @@ +# Dhall {#sec-language-dhall} + +The Nixpkgs support for Dhall assumes some familiarity with Dhall's language +support for importing Dhall expressions, which is documented here: + +* [`dhall-lang.org` - Installing packages](https://docs.dhall-lang.org/tutorials/Language-Tour.html#installing-packages) + +## Remote imports {#ssec-dhall-remote-imports} + +Nixpkgs bypasses Dhall's support for remote imports using Dhall's +semantic integrity checks. Specifically, any Dhall import can be protected by +an integrity check like: + +```dhall +https://prelude.dhall-lang.org/v20.1.0/package.dhall + sha256:26b0ef498663d269e4dc6a82b0ee289ec565d683ef4c00d0ebdd25333a5a3c98 +``` + +… and if the import is cached then the interpreter will load the import from +cache instead of fetching the URL. + +Nixpkgs uses this trick to add all of a Dhall expression's dependencies into the +cache so that the Dhall interpreter never needs to resolve any remote URLs. In +fact, Nixpkgs uses a Dhall interpreter with remote imports disabled when +packaging Dhall expressions to enforce that the interpreter never resolves a +remote import. This means that Nixpkgs only supports building Dhall expressions +if all of their remote imports are protected by semantic integrity checks. + +Instead of remote imports, Nixpkgs uses Nix to fetch remote Dhall code. For +example, the Prelude Dhall package uses `pkgs.fetchFromGitHub` to fetch the +`dhall-lang` repository containing the Prelude. Relying exclusively on Nix +to fetch Dhall code ensures that Dhall packages built using Nix remain pure and +also behave well when built within a sandbox. + +## Packaging a Dhall expression from scratch {#ssec-dhall-packaging-expression} + +We can illustrate how Nixpkgs integrates Dhall by beginning from the following +trivial Dhall expression with one dependency (the Prelude): + +```dhall +-- ./true.dhall + +let Prelude = https://prelude.dhall-lang.org/v20.1.0/package.dhall + +in Prelude.Bool.not False +``` + +As written, this expression cannot be built using Nixpkgs because the +expression does not protect the Prelude import with a semantic integrity +check, so the first step is to freeze the expression using `dhall freeze`, +like this: + +```ShellSession +$ dhall freeze --inplace ./true.dhall +``` + +… which gives us: + +```dhall +-- ./true.dhall + +let Prelude = + https://prelude.dhall-lang.org/v20.1.0/package.dhall + sha256:26b0ef498663d269e4dc6a82b0ee289ec565d683ef4c00d0ebdd25333a5a3c98 + +in Prelude.Bool.not False +``` + +To package that expression, we create a `./true.nix` file containing the +following specification for the Dhall package: + +```nix +# ./true.nix + +{ buildDhallPackage, Prelude }: + +buildDhallPackage { + name = "true"; + code = ./true.dhall; + dependencies = [ Prelude ]; + source = true; +} +``` + +… and we complete the build by incorporating that Dhall package into the +`pkgs.dhallPackages` hierarchy using an overlay, like this: + +```nix +# ./example.nix + +let + nixpkgs = builtins.fetchTarball { + url = "https://github.com/NixOS/nixpkgs/archive/94b2848559b12a8ed1fe433084686b2a81123c99.tar.gz"; + sha256 = "1pbl4c2dsaz2lximgd31m96jwbps6apn3anx8cvvhk1gl9rkg107"; + }; + + dhallOverlay = self: super: { + true = self.callPackage ./true.nix { }; + }; + + overlay = self: super: { + dhallPackages = super.dhallPackages.override (old: { + overrides = + self.lib.composeExtensions (old.overrides or (_: _: {})) dhallOverlay; + }); + }; + + pkgs = import nixpkgs { config = {}; overlays = [ overlay ]; }; + +in + pkgs +``` + +… which we can then build using this command: + +```ShellSession +$ nix build --file ./example.nix dhallPackages.true +``` + +## Contents of a Dhall package {#ssec-dhall-package-contents} + +The above package produces the following directory tree: + +```ShellSession +$ tree -a ./result +result +├── .cache +│ └── dhall +│ └── 122027abdeddfe8503496adeb623466caa47da5f63abd2bc6fa19f6cfcb73ecfed70 +├── binary.dhall +└── source.dhall +``` + +… where: + +* `source.dhall` contains the result of interpreting our Dhall package: + + ```ShellSession + $ cat ./result/source.dhall + True + ``` + +* The `.cache` subdirectory contains one binary cache product encoding the + same result as `source.dhall`: + + ```ShellSession + $ dhall decode < ./result/.cache/dhall/122027abdeddfe8503496adeb623466caa47da5f63abd2bc6fa19f6cfcb73ecfed70 + True + ``` + +* `binary.dhall` contains a Dhall expression which handles fetching and decoding + the same cache product: + + ```ShellSession + $ cat ./result/binary.dhall + missing sha256:27abdeddfe8503496adeb623466caa47da5f63abd2bc6fa19f6cfcb73ecfed70 + $ cp -r ./result/.cache .cache + + $ chmod -R u+w .cache + + $ XDG_CACHE_HOME=.cache dhall --file ./result/binary.dhall + True + ``` + +The `source.dhall` file is only present for packages that specify +`source = true;`. By default, Dhall packages omit the `source.dhall` in order +to conserve disk space when they are used exclusively as dependencies. For +example, if we build the Prelude package it will only contain the binary +encoding of the expression: + +```ShellSession +$ nix build --file ./example.nix dhallPackages.Prelude + +$ tree -a result +result +├── .cache +│ └── dhall +│ └── 122026b0ef498663d269e4dc6a82b0ee289ec565d683ef4c00d0ebdd25333a5a3c98 +└── binary.dhall + +2 directories, 2 files +``` + +Typically, you only specify `source = true;` for the top-level Dhall expression +of interest (such as our example `true.nix` Dhall package). However, if you +wish to specify `source = true` for all Dhall packages, then you can amend the +Dhall overlay like this: + +```nix + dhallOverrides = self: super: { + # Enable source for all Dhall packages + buildDhallPackage = + args: super.buildDhallPackage (args // { source = true; }); + + true = self.callPackage ./true.nix { }; + }; +``` + +… and now the Prelude will contain the fully decoded result of interpreting +the Prelude: + +```ShellSession +$ nix build --file ./example.nix dhallPackages.Prelude + +$ tree -a result +result +├── .cache +│ └── dhall +│ └── 122026b0ef498663d269e4dc6a82b0ee289ec565d683ef4c00d0ebdd25333a5a3c98 +├── binary.dhall +└── source.dhall + +$ cat ./result/source.dhall +{ Bool = + { and = + \(_ : List Bool) -> + List/fold Bool _ Bool (\(_ : Bool) -> \(_ : Bool) -> _@1 && _) True + , build = \(_ : Type -> _ -> _@1 -> _@2) -> _ Bool True False + , even = + \(_ : List Bool) -> + List/fold Bool _ Bool (\(_ : Bool) -> \(_ : Bool) -> _@1 == _) True + , fold = + \(_ : Bool) -> +… +``` + +## Packaging functions {#ssec-dhall-packaging-functions} + +We already saw an example of using `buildDhallPackage` to create a Dhall +package from a single file, but most Dhall packages consist of more than one +file and there are two derived utilities that you may find more useful when +packaging multiple files: + +* `buildDhallDirectoryPackage` - build a Dhall package from a local directory + +* `buildDhallGitHubPackage` - build a Dhall package from a GitHub repository + +The `buildDhallPackage` is the lowest-level function and accepts the following +arguments: + +* `name`: The name of the derivation + +* `dependencies`: Dhall dependencies to build and cache ahead of time + +* `code`: The top-level expression to build for this package + + Note that the `code` field accepts an arbitrary Dhall expression. You're + not limited to just a file. + +* `source`: Set to `true` to include the decoded result as `source.dhall` in the + build product, at the expense of requiring more disk space + +* `documentationRoot`: Set to the root directory of the package if you want + `dhall-docs` to generate documentation underneath the `docs` subdirectory of + the build product + +The `buildDhallDirectoryPackage` is a higher-level function implemented in terms +of `buildDhallPackage` that accepts the following arguments: + +* `name`: Same as `buildDhallPackage` + +* `dependencies`: Same as `buildDhallPackage` + +* `source`: Same as `buildDhallPackage` + +* `src`: The directory containing Dhall code that you want to turn into a Dhall + package + +* `file`: The top-level file (`package.dhall` by default) that is the entrypoint + to the rest of the package + +* `document`: Set to `true` to generate documentation for the package + +The `buildDhallGitHubPackage` is another higher-level function implemented in +terms of `buildDhallPackage` that accepts the following arguments: + +* `name`: Same as `buildDhallPackage` + +* `dependencies`: Same as `buildDhallPackage` + +* `source`: Same as `buildDhallPackage` + +* `owner`: The owner of the repository + +* `repo`: The repository name + +* `rev`: The desired revision (or branch, or tag) + +* `directory`: The subdirectory of the Git repository to package (if a + directory other than the root of the repository) + +* `file`: The top-level file (`${directory}/package.dhall` by default) that is + the entrypoint to the rest of the package + +* `document`: Set to `true` to generate documentation for the package + +Additionally, `buildDhallGitHubPackage` accepts the same arguments as +`fetchFromGitHub`, such as `sha256` or `fetchSubmodules`. + +## `dhall-to-nixpkgs` {#ssec-dhall-dhall-to-nixpkgs} + +You can use the `dhall-to-nixpkgs` command-line utility to automate +packaging Dhall code. For example: + +```ShellSession +$ nix-env --install --attr haskellPackages.dhall-nixpkgs + +$ nix-env --install --attr nix-prefetch-git # Used by dhall-to-nixpkgs + +$ dhall-to-nixpkgs github https://github.com/Gabriel439/dhall-semver.git +{ buildDhallGitHubPackage, Prelude }: + buildDhallGitHubPackage { + name = "dhall-semver"; + githubBase = "github.com"; + owner = "Gabriel439"; + repo = "dhall-semver"; + rev = "2d44ae605302ce5dc6c657a1216887fbb96392a4"; + fetchSubmodules = false; + sha256 = "0y8shvp8srzbjjpmnsvz9c12ciihnx1szs0yzyi9ashmrjvd0jcz"; + directory = ""; + file = "package.dhall"; + source = false; + document = false; + dependencies = [ (Prelude.overridePackage { file = "package.dhall"; }) ]; + } +``` + +The utility takes care of automatically detecting remote imports and converting +them to package dependencies. You can also use the utility on local +Dhall directories, too: + +```ShellSession +$ dhall-to-nixpkgs directory ~/proj/dhall-semver +{ buildDhallDirectoryPackage, Prelude }: + buildDhallDirectoryPackage { + name = "proj"; + src = ~/proj/dhall-semver; + file = "package.dhall"; + source = false; + document = false; + dependencies = [ (Prelude.overridePackage { file = "package.dhall"; }) ]; + } +``` + +### Remote imports as fixed-output derivations {#ssec-dhall-remote-imports-as-fod} + +`dhall-to-nixpkgs` has the ability to fetch and build remote imports as +fixed-output derivations by using their Dhall integrity check. This is +sometimes easier than manually packaging all remote imports. + +This can be used like the following: + +```ShellSession +$ dhall-to-nixpkgs directory --fixed-output-derivations ~/proj/dhall-semver +{ buildDhallDirectoryPackage, buildDhallUrl }: + buildDhallDirectoryPackage { + name = "proj"; + src = ~/proj/dhall-semver; + file = "package.dhall"; + source = false; + document = false; + dependencies = [ + (buildDhallUrl { + url = "https://prelude.dhall-lang.org/v17.0.0/package.dhall"; + hash = "sha256-ENs8kZwl6QRoM9+Jeo/+JwHcOQ+giT2VjDQwUkvlpD4="; + dhallHash = "sha256:10db3c919c25e9046833df897a8ffe2701dc390fa0893d958c3430524be5a43e"; + }) + ]; + } +``` + +Here, `dhall-semver`'s `Prelude` dependency is fetched and built with the +`buildDhallUrl` helper function, instead of being passed in as a function +argument. + +## Overriding dependency versions {#ssec-dhall-overriding-dependency-versions} + +Suppose that we change our `true.dhall` example expression to depend on an older +version of the Prelude (19.0.0): + +```dhall +-- ./true.dhall + +let Prelude = + https://prelude.dhall-lang.org/v19.0.0/package.dhall + sha256:eb693342eb769f782174157eba9b5924cf8ac6793897fc36a31ccbd6f56dafe2 + +in Prelude.Bool.not False +``` + +If we try to rebuild that expression the build will fail: + +```ShellSession +$ nix build --file ./example.nix dhallPackages.true +builder for '/nix/store/0f1hla7ff1wiaqyk1r2ky4wnhnw114fi-true.drv' failed with exit code 1; last 10 log lines: + + Dhall was compiled without the 'with-http' flag. + + The requested URL was: https://prelude.dhall-lang.org/v19.0.0/package.dhall + + + 4│ https://prelude.dhall-lang.org/v19.0.0/package.dhall + 5│ sha256:eb693342eb769f782174157eba9b5924cf8ac6793897fc36a31ccbd6f56dafe2 + + /nix/store/rsab4y99h14912h4zplqx2iizr5n4rc2-true.dhall:4:7 +[1 built (1 failed), 0.0 MiB DL] +error: build of '/nix/store/0f1hla7ff1wiaqyk1r2ky4wnhnw114fi-true.drv' failed +``` + +… because the default Prelude selected by Nixpkgs revision +`94b2848559b12a8ed1fe433084686b2a81123c99is` is version 20.1.0, which doesn't +have the same integrity check as version 19.0.0. This means that version +19.0.0 is not cached and the interpreter is not allowed to fall back to +importing the URL. + +However, we can override the default Prelude version by using `dhall-to-nixpkgs` +to create a Dhall package for our desired Prelude: + +```ShellSession +$ dhall-to-nixpkgs github https://github.com/dhall-lang/dhall-lang.git \ + --name Prelude \ + --directory Prelude \ + --rev v19.0.0 \ + > Prelude.nix +``` + +… and then referencing that package in our Dhall overlay, by either overriding +the Prelude globally for all packages, like this: + +```nix + dhallOverrides = self: super: { + true = self.callPackage ./true.nix { }; + + Prelude = self.callPackage ./Prelude.nix { }; + }; +``` + +… or selectively overriding the Prelude dependency for just the `true` package, +like this: + +```nix + dhallOverrides = self: super: { + true = self.callPackage ./true.nix { + Prelude = self.callPackage ./Prelude.nix { }; + }; + }; +``` + +## Overrides {#ssec-dhall-overrides} + +You can override any of the arguments to `buildDhallGitHubPackage` or +`buildDhallDirectoryPackage` using the `overridePackage` attribute of a package. +For example, suppose we wanted to selectively enable `source = true` just for the Prelude. We can do that like this: + +```nix + dhallOverrides = self: super: { + Prelude = super.Prelude.overridePackage { source = true; }; + + … + }; +``` + +[semantic-integrity-checks]: https://docs.dhall-lang.org/tutorials/Language-Tour.html#installing-packages diff --git a/doc/languages-frameworks/dotnet.section.md b/doc/languages-frameworks/dotnet.section.md new file mode 100644 index 00000000000..f7af28a1677 --- /dev/null +++ b/doc/languages-frameworks/dotnet.section.md @@ -0,0 +1,132 @@ +# Dotnet {#dotnet} + +## Local Development Workflow {#local-development-workflow} + +For local development, it's recommended to use nix-shell to create a dotnet environment: + +```nix +# shell.nix +with import <nixpkgs> {}; + +mkShell { + name = "dotnet-env"; + packages = [ + dotnet-sdk_3 + ]; +} +``` + +### Using many sdks in a workflow {#using-many-sdks-in-a-workflow} + +It's very likely that more than one sdk will be needed on a given project. Dotnet provides several different frameworks (E.g dotnetcore, aspnetcore, etc.) as well as many versions for a given framework. Normally, dotnet is able to fetch a framework and install it relative to the executable. However, this would mean writing to the nix store in nixpkgs, which is read-only. To support the many-sdk use case, one can compose an environment using `dotnetCorePackages.combinePackages`: + +```nix +with import <nixpkgs> {}; + +mkShell { + name = "dotnet-env"; + packages = [ + (with dotnetCorePackages; combinePackages [ + sdk_3_1 + sdk_5_0 + ]) + ]; +} +``` + +This will produce a dotnet installation that has the dotnet 3.1, 3.0, and 2.1 sdk. The first sdk listed will have it's cli utility present in the resulting environment. Example info output: + +```ShellSession +$ dotnet --info +.NET Core SDK (reflecting any global.json): + Version: 3.1.101 + Commit: b377529961 + +... + +.NET Core SDKs installed: + 2.1.803 [/nix/store/iiv98i2jdi226dgh4jzkkj2ww7f8jgpd-dotnet-core-combined/sdk] + 3.0.102 [/nix/store/iiv98i2jdi226dgh4jzkkj2ww7f8jgpd-dotnet-core-combined/sdk] + 3.1.101 [/nix/store/iiv98i2jdi226dgh4jzkkj2ww7f8jgpd-dotnet-core-combined/sdk] + +.NET Core runtimes installed: + Microsoft.AspNetCore.All 2.1.15 [/nix/store/iiv98i2jdi226dgh4jzkkj2ww7f8jgpd-dotnet-core-combined/shared/Microsoft.AspNetCore.All] + Microsoft.AspNetCore.App 2.1.15 [/nix/store/iiv98i2jdi226dgh4jzkkj2ww7f8jgpd-dotnet-core-combined/shared/Microsoft.AspNetCore.App] + Microsoft.AspNetCore.App 3.0.2 [/nix/store/iiv98i2jdi226dgh4jzkkj2ww7f8jgpd-dotnet-core-combined/shared/Microsoft.AspNetCore.App] + Microsoft.AspNetCore.App 3.1.1 [/nix/store/iiv98i2jdi226dgh4jzkkj2ww7f8jgpd-dotnet-core-combined/shared/Microsoft.AspNetCore.App] + Microsoft.NETCore.App 2.1.15 [/nix/store/iiv98i2jdi226dgh4jzkkj2ww7f8jgpd-dotnet-core-combined/shared/Microsoft.NETCore.App] + Microsoft.NETCore.App 3.0.2 [/nix/store/iiv98i2jdi226dgh4jzkkj2ww7f8jgpd-dotnet-core-combined/shared/Microsoft.NETCore.App] + Microsoft.NETCore.App 3.1.1 [/nix/store/iiv98i2jdi226dgh4jzkkj2ww7f8jgpd-dotnet-core-combined/shared/Microsoft.NETCore.App] +``` + +## dotnet-sdk vs dotnetCorePackages.sdk {#dotnet-sdk-vs-dotnetcorepackages.sdk} + +The `dotnetCorePackages.sdk_X_Y` is preferred over the old dotnet-sdk as both major and minor version are very important for a dotnet environment. If a given minor version isn't present (or was changed), then this will likely break your ability to build a project. + +## dotnetCorePackages.sdk vs dotnetCorePackages.runtime vs dotnetCorePackages.aspnetcore {#dotnetcorepackages.sdk-vs-dotnetcorepackages.runtime-vs-dotnetcorepackages.aspnetcore} + +The `dotnetCorePackages.sdk` contains both a runtime and the full sdk of a given version. The `runtime` and `aspnetcore` packages are meant to serve as minimal runtimes to deploy alongside already built applications. + +## Packaging a Dotnet Application {#packaging-a-dotnet-application} + +To package Dotnet applications, you can use `buildDotnetModule`. This has similar arguments to `stdenv.mkDerivation`, with the following additions: + +* `projectFile` has to be used for specifying the dotnet project file relative to the source root. These usually have `.sln` or `.csproj` file extensions. This can be an array of multiple projects as well. +* `nugetDeps` has to be used to specify the NuGet dependency file. Unfortunately, these cannot be deterministically fetched without a lockfile. A script to fetch these is available as `passthru.fetch-deps`. This file can also be generated manually using `nuget-to-nix` tool, which is available in nixpkgs. +* `packNupkg` is used to pack project as a `nupkg`, and installs it to `$out/share`. If set to `true`, the derivation can be used as a dependency for another dotnet project by adding it to `projectReferences`. +* `projectReferences` can be used to resolve `ProjectReference` project items. Referenced projects can be packed with `buildDotnetModule` by setting the `packNupkg = true` attribute and passing a list of derivations to `projectReferences`. Since we are sharing referenced projects as NuGets they must be added to csproj/fsproj files as `PackageReference` as well. + For example, your project has a local dependency: + ```xml + <ProjectReference Include="../foo/bar.fsproj" /> + ``` + To enable discovery through `projectReferences` you would need to add: + ```xml + <ProjectReference Include="../foo/bar.fsproj" /> + <PackageReference Include="bar" Version="*" Condition=" '$(ContinuousIntegrationBuild)'=='true' "/> + ``` +* `executables` is used to specify which executables get wrapped to `$out/bin`, relative to `$out/lib/$pname`. If this is unset, all executables generated will get installed. If you do not want to install any, set this to `[]`. This gets done in the `preFixup` phase. +* `runtimeDeps` is used to wrap libraries into `LD_LIBRARY_PATH`. This is how dotnet usually handles runtime dependencies. +* `buildType` is used to change the type of build. Possible values are `Release`, `Debug`, etc. By default, this is set to `Release`. +* `dotnet-sdk` is useful in cases where you need to change what dotnet SDK is being used. +* `dotnet-runtime` is useful in cases where you need to change what dotnet runtime is being used. This can be either a regular dotnet runtime, or an aspnetcore. +* `dotnet-test-sdk` is useful in cases where unit tests expect a different dotnet SDK. By default, this is set to the `dotnet-sdk` attribute. +* `testProjectFile` is useful in cases where the regular project file does not contain the unit tests. It gets restored and build, but not installed. You may need to regenerate your nuget lockfile after setting this. +* `disabledTests` is used to disable running specific unit tests. This gets passed as: `dotnet test --filter "FullyQualifiedName!={}"`, to ensure compatibility with all unit test frameworks. +* `dotnetRestoreFlags` can be used to pass flags to `dotnet restore`. +* `dotnetBuildFlags` can be used to pass flags to `dotnet build`. +* `dotnetTestFlags` can be used to pass flags to `dotnet test`. Used only if `doCheck` is set to `true`. +* `dotnetInstallFlags` can be used to pass flags to `dotnet install`. +* `dotnetPackFlags` can be used to pass flags to `dotnet pack`. Used only if `packNupkg` is set to `true`. +* `dotnetFlags` can be used to pass flags to all of the above phases. + +When packaging a new application, you need to fetch it's dependencies. You can set `nugetDeps` to an empty string to make the derivation temporarily evaluate, and then run `nix-build -A package.passthru.fetch-deps` to generate it's dependency fetching script. After running the script, you should have the location of the generated lockfile printed to the console. This can be copied to a stable directory. Note that if either `projectFile` or `nugetDeps` are unset, this script cannot be generated! + +Here is an example `default.nix`, using some of the previously discussed arguments: +```nix +{ lib, buildDotnetModule, dotnetCorePackages, ffmpeg }: + +let + referencedProject = import ../../bar { ... }; +in buildDotnetModule rec { + pname = "someDotnetApplication"; + version = "0.1"; + + src = ./.; + + projectFile = "src/project.sln"; + nugetDeps = ./deps.nix; # File generated with `nix-build -A package.passthru.fetch-deps`. + + projectReferences = [ referencedProject ]; # `referencedProject` must contain `nupkg` in the folder structure. + + dotnet-sdk = dotnetCorePackages.sdk_3_1; + dotnet-runtime = dotnetCorePackages.net_5_0; + dotnetFlags = [ "--runtime linux-x64" ]; + + executables = [ "foo" ]; # This wraps "$out/lib/$pname/foo" to `$out/bin/foo`. + executables = []; # Don't install any executables. + + packNupkg = true; # This packs the project as "foo-0.1.nupkg" at `$out/share`. + + runtimeDeps = [ ffmpeg ]; # This will wrap ffmpeg's library path into `LD_LIBRARY_PATH`. +} +``` diff --git a/doc/languages-frameworks/emscripten.section.md b/doc/languages-frameworks/emscripten.section.md new file mode 100644 index 00000000000..c96f689c4c0 --- /dev/null +++ b/doc/languages-frameworks/emscripten.section.md @@ -0,0 +1,182 @@ +# Emscripten {#emscripten} + +[Emscripten](https://github.com/kripken/emscripten): An LLVM-to-JavaScript Compiler + +This section of the manual covers how to use `emscripten` in nixpkgs. + +Minimal requirements: + +* nix +* nixpkgs + +Modes of use of `emscripten`: + +* **Imperative usage** (on the command line): + + If you want to work with `emcc`, `emconfigure` and `emmake` as you are used to from Ubuntu and similar distributions you can use these commands: + + * `nix-env -f "<nixpkgs>" -iA emscripten` + * `nix-shell -p emscripten` + +* **Declarative usage**: + + This mode is far more power full since this makes use of `nix` for dependency management of emscripten libraries and targets by using the `mkDerivation` which is implemented by `pkgs.emscriptenStdenv` and `pkgs.buildEmscriptenPackage`. The source for the packages is in `pkgs/top-level/emscripten-packages.nix` and the abstraction behind it in `pkgs/development/em-modules/generic/default.nix`. From the root of the nixpkgs repository: + * build and install all packages: + * `nix-env -iA emscriptenPackages` + + * dev-shell for zlib implementation hacking: + * `nix-shell -A emscriptenPackages.zlib` + +## Imperative usage {#imperative-usage} + +A few things to note: + +* `export EMCC_DEBUG=2` is nice for debugging +* `~/.emscripten`, the build artifact cache sometimes creates issues and needs to be removed from time to time + +## Declarative usage {#declarative-usage} + +Let's see two different examples from `pkgs/top-level/emscripten-packages.nix`: + +* `pkgs.zlib.override` +* `pkgs.buildEmscriptenPackage` + +Both are interesting concepts. + +A special requirement of the `pkgs.buildEmscriptenPackage` is the `doCheck = true` is a default meaning that each emscriptenPackage requires a `checkPhase` implemented. + +* Use `export EMCC_DEBUG=2` from within a emscriptenPackage's `phase` to get more detailed debug output what is going wrong. +* ~/.emscripten cache is requiring us to set `HOME=$TMPDIR` in individual phases. This makes compilation slower but also makes it more deterministic. + +### Usage 1: pkgs.zlib.override {#usage-1-pkgs.zlib.override} + +This example uses `zlib` from nixpkgs but instead of compiling **C** to **ELF** it compiles **C** to **JS** since we were using `pkgs.zlib.override` and changed stdenv to `pkgs.emscriptenStdenv`. A few adaptions and hacks were set in place to make it working. One advantage is that when `pkgs.zlib` is updated, it will automatically update this package as well. However, this can also be the downside... + +See the `zlib` example: + + zlib = (pkgs.zlib.override { + stdenv = pkgs.emscriptenStdenv; + }).overrideDerivation + (old: rec { + buildInputs = old.buildInputs ++ [ pkg-config ]; + # we need to reset this setting! + NIX_CFLAGS_COMPILE=""; + configurePhase = '' + # FIXME: Some tests require writing at $HOME + HOME=$TMPDIR + runHook preConfigure + + #export EMCC_DEBUG=2 + emconfigure ./configure --prefix=$out --shared + + runHook postConfigure + ''; + dontStrip = true; + outputs = [ "out" ]; + buildPhase = '' + emmake make + ''; + installPhase = '' + emmake make install + ''; + checkPhase = '' + echo "================= testing zlib using node =================" + + echo "Compiling a custom test" + set -x + emcc -O2 -s EMULATE_FUNCTION_POINTER_CASTS=1 test/example.c -DZ_SOLO \ + libz.so.${old.version} -I . -o example.js + + echo "Using node to execute the test" + ${pkgs.nodejs}/bin/node ./example.js + + set +x + if [ $? -ne 0 ]; then + echo "test failed for some reason" + exit 1; + else + echo "it seems to work! very good." + fi + echo "================= /testing zlib using node =================" + ''; + + postPatch = pkgs.lib.optionalString pkgs.stdenv.isDarwin '' + substituteInPlace configure \ + --replace '/usr/bin/libtool' 'ar' \ + --replace 'AR="libtool"' 'AR="ar"' \ + --replace 'ARFLAGS="-o"' 'ARFLAGS="-r"' + ''; + }); + +### Usage 2: pkgs.buildEmscriptenPackage {#usage-2-pkgs.buildemscriptenpackage} + +This `xmlmirror` example features a emscriptenPackage which is defined completely from this context and no `pkgs.zlib.override` is used. + + xmlmirror = pkgs.buildEmscriptenPackage rec { + name = "xmlmirror"; + + buildInputs = [ pkg-config autoconf automake libtool gnumake libxml2 nodejs openjdk json_c ]; + nativeBuildInputs = [ pkg-config zlib ]; + + src = pkgs.fetchgit { + url = "https://gitlab.com/odfplugfest/xmlmirror.git"; + rev = "4fd7e86f7c9526b8f4c1733e5c8b45175860a8fd"; + sha256 = "1jasdqnbdnb83wbcnyrp32f36w3xwhwp0wq8lwwmhqagxrij1r4b"; + }; + + configurePhase = '' + rm -f fastXmlLint.js* + # a fix for ERROR:root:For asm.js, TOTAL_MEMORY must be a multiple of 16MB, was 234217728 + # https://gitlab.com/odfplugfest/xmlmirror/issues/8 + sed -e "s/TOTAL_MEMORY=234217728/TOTAL_MEMORY=268435456/g" -i Makefile.emEnv + # https://github.com/kripken/emscripten/issues/6344 + # https://gitlab.com/odfplugfest/xmlmirror/issues/9 + sed -e "s/\$(JSONC_LDFLAGS) \$(ZLIB_LDFLAGS) \$(LIBXML20_LDFLAGS)/\$(JSONC_LDFLAGS) \$(LIBXML20_LDFLAGS) \$(ZLIB_LDFLAGS) /g" -i Makefile.emEnv + # https://gitlab.com/odfplugfest/xmlmirror/issues/11 + sed -e "s/-o fastXmlLint.js/-s EXTRA_EXPORTED_RUNTIME_METHODS='[\"ccall\", \"cwrap\"]' -o fastXmlLint.js/g" -i Makefile.emEnv + ''; + + buildPhase = '' + HOME=$TMPDIR + make -f Makefile.emEnv + ''; + + outputs = [ "out" "doc" ]; + + installPhase = '' + mkdir -p $out/share + mkdir -p $doc/share/${name} + + cp Demo* $out/share + cp -R codemirror-5.12 $out/share + cp fastXmlLint.js* $out/share + cp *.xsd $out/share + cp *.js $out/share + cp *.xhtml $out/share + cp *.html $out/share + cp *.json $out/share + cp *.rng $out/share + cp README.md $doc/share/${name} + ''; + checkPhase = '' + + ''; + }; + +### Declarative debugging {#declarative-debugging} + +Use `nix-shell -I nixpkgs=/some/dir/nixpkgs -A emscriptenPackages.libz` and from there you can go trough the individual steps. This makes it easy to build a good `unit test` or list the files of the project. + +1. `nix-shell -I nixpkgs=/some/dir/nixpkgs -A emscriptenPackages.libz` +2. `cd /tmp/` +3. `unpackPhase` +4. cd libz-1.2.3 +5. `configurePhase` +6. `buildPhase` +7. ... happy hacking... + +## Summary {#summary} + +Using this toolchain makes it easy to leverage `nix` from NixOS, MacOSX or even Windows (WSL+ubuntu+nix). This toolchain is reproducible, behaves like the rest of the packages from nixpkgs and contains a set of well working examples to learn and adapt from. + +If in trouble, ask the maintainers. diff --git a/doc/languages-frameworks/gnome.section.md b/doc/languages-frameworks/gnome.section.md new file mode 100644 index 00000000000..29cb2e0e464 --- /dev/null +++ b/doc/languages-frameworks/gnome.section.md @@ -0,0 +1,204 @@ +# GNOME {#sec-language-gnome} + +## Packaging GNOME applications {#ssec-gnome-packaging} + +Programs in the GNOME universe are written in various languages but they all use GObject-based libraries like GLib, GTK or GStreamer. These libraries are often modular, relying on looking into certain directories to find their modules. However, due to Nix’s specific file system organization, this will fail without our intervention. Fortunately, the libraries usually allow overriding the directories through environment variables, either natively or thanks to a patch in nixpkgs. [Wrapping](#fun-wrapProgram) the executables to ensure correct paths are available to the application constitutes a significant part of packaging a modern desktop application. In this section, we will describe various modules needed by such applications, environment variables needed to make the modules load, and finally a script that will do the work for us. + +### Settings {#ssec-gnome-settings} + +[GSettings](https://developer.gnome.org/gio/stable/GSettings.html) API is often used for storing settings. GSettings schemas are required, to know the type and other metadata of the stored values. GLib looks for `glib-2.0/schemas/gschemas.compiled` files inside the directories of `XDG_DATA_DIRS`. + +On Linux, GSettings API is implemented using [dconf](https://wiki.gnome.org/Projects/dconf) backend. You will need to add `dconf` [GIO module](#ssec-gnome-gio-modules) to `GIO_EXTRA_MODULES` variable, otherwise the `memory` backend will be used and the saved settings will not be persistent. + +Last you will need the dconf database D-Bus service itself. You can enable it using `programs.dconf.enable`. + +Some applications will also require `gsettings-desktop-schemas` for things like reading proxy configuration or user interface customization. This dependency is often not mentioned by upstream, you should grep for `org.gnome.desktop` and `org.gnome.system` to see if the schemas are needed. + +### GIO modules {#ssec-gnome-gio-modules} + +GLib’s [GIO](https://developer.gnome.org/gio/stable/ch01.html) library supports several [extension points](https://developer.gnome.org/gio/stable/extending-gio.html). Notably, they allow: + +* implementing settings backends (already [mentioned](#ssec-gnome-settings)) +* adding TLS support +* proxy settings +* virtual file systems + +The modules are typically installed to `lib/gio/modules/` directory of a package and you need to add them to `GIO_EXTRA_MODULES` if you need any of those features. + +In particular, we recommend: + +* adding `dconf.lib` for any software on Linux that reads [GSettings](#ssec-gnome-settings) (even transitivily through e.g. GTK’s file manager) +* adding `glib-networking` for any software that accesses network using GIO or libsoup – glib-networking contains a module that implements TLS support and loads system-wide proxy settings + +To allow software to use various virtual file systems, `gvfs` package can be also added. But that is usually an optional feature so we typically use `gvfs` from the system (e.g. installed globally using NixOS module). + +### GdkPixbuf loaders {#ssec-gnome-gdk-pixbuf-loaders} + +GTK applications typically use [GdkPixbuf](https://developer.gnome.org/gdk-pixbuf/stable/) to load images. But `gdk-pixbuf` package only supports basic bitmap formats like JPEG, PNG or TIFF, requiring to use third-party loader modules for other formats. This is especially painful since GTK itself includes SVG icons, which cannot be rendered without a loader provided by `librsvg`. + +Unlike other libraries mentioned in this section, GdkPixbuf only supports a single value in its controlling environment variable `GDK_PIXBUF_MODULE_FILE`. It is supposed to point to a cache file containing information about the available loaders. Each loader package will contain a `lib/gdk-pixbuf-2.0/2.10.0/loaders.cache` file describing the default loaders in `gdk-pixbuf` package plus the loader contained in the package itself. If you want to use multiple third-party loaders, you will need to create your own cache file manually. Fortunately, this is pretty rare as [not many loaders exist](https://gitlab.gnome.org/federico/gdk-pixbuf-survey/blob/master/src/modules.md). + +`gdk-pixbuf` contains [a setup hook](#ssec-gnome-hooks-gdk-pixbuf) that sets `GDK_PIXBUF_MODULE_FILE` from dependencies but as mentioned in further section, it is pretty limited. Loaders should propagate this setup hook. + +### Icons {#ssec-gnome-icons} + +When an application uses icons, an icon theme should be available in `XDG_DATA_DIRS` during runtime. The package for the default, icon-less [hicolor-icon-theme](https://www.freedesktop.org/wiki/Software/icon-theme/) (should be propagated by every icon theme) contains [a setup hook](#ssec-gnome-hooks-hicolor-icon-theme) that will pick up icon themes from `buildInputs` and pass it to our wrapper. Unfortunately, relying on that would mean every user has to download the theme included in the package expression no matter their preference. For that reason, we leave the installation of icon theme on the user. If you use one of the desktop environments, you probably already have an icon theme installed. + +To avoid costly file system access when locating icons, GTK, [as well as Qt](https://woboq.com/blog/qicon-reads-gtk-icon-cache-in-qt57.html), can rely on `icon-theme.cache` files from the themes' top-level directories. These files are generated using `gtk-update-icon-cache`, which is expected to be run whenever an icon is added or removed to an icon theme (typically an application icon into `hicolor` theme) and some programs do indeed run this after icon installation. However, since packages are installed into their own prefix by Nix, this would lead to conflicts. For that reason, `gtk3` provides a [setup hook](#ssec-gnome-hooks-gtk-drop-icon-theme-cache) that will clean the file from installation. Since most applications only ship their own icon that will be loaded on start-up, it should not affect them too much. On the other hand, icon themes are much larger and more widely used so we need to cache them. Because we recommend installing icon themes globally, we will generate the cache files from all packages in a profile using a NixOS module. You can enable the cache generation using `gtk.iconCache.enable` option if your desktop environment does not already do that. + +### Packaging icon themes {#ssec-icon-theme-packaging} + +Icon themes may inherit from other icon themes. The inheritance is specified using the `Inherits` key in the `index.theme` file distributed with the icon theme. According to the [icon theme specification](https://specifications.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html), icons not provided by the theme are looked for in its parent icon themes. Therefore the parent themes should be installed as dependencies for a more complete experience regarding the icon sets used. + +The package `hicolor-icon-theme` provides a setup hook which makes symbolic links for the parent themes into the directory `share/icons` of the current theme directory in the nix store, making sure they can be found at runtime. For that to work the packages providing parent icon themes should be listed as propagated build dependencies, together with `hicolor-icon-theme`. + +Also make sure that `icon-theme.cache` is installed for each theme provided by the package, and set `dontDropIconThemeCache` to `true` so that the cache file is not removed by the `gtk3` setup hook. + +### GTK Themes {#ssec-gnome-themes} + +Previously, a GTK theme needed to be in `XDG_DATA_DIRS`. This is no longer necessary for most programs since GTK incorporated Adwaita theme. Some programs (for example, those designed for [elementary HIG](https://elementary.io/docs/human-interface-guidelines#human-interface-guidelines)) might require a special theme like `pantheon.elementary-gtk-theme`. + +### GObject introspection typelibs {#ssec-gnome-typelibs} + +[GObject introspection](https://wiki.gnome.org/Projects/GObjectIntrospection) allows applications to use C libraries in other languages easily. It does this through `typelib` files searched in `GI_TYPELIB_PATH`. + +### Various plug-ins {#ssec-gnome-plugins} + +If your application uses [GStreamer](https://gstreamer.freedesktop.org/) or [Grilo](https://wiki.gnome.org/Projects/Grilo), you should set `GST_PLUGIN_SYSTEM_PATH_1_0` and `GRL_PLUGIN_PATH`, respectively. + +## Onto `wrapGAppsHook` {#ssec-gnome-hooks} + +Given the requirements above, the package expression would become messy quickly: + +```nix +preFixup = '' + for f in $(find $out/bin/ $out/libexec/ -type f -executable); do + wrapProgram "$f" \ + --prefix GIO_EXTRA_MODULES : "${getLib dconf}/lib/gio/modules" \ + --prefix XDG_DATA_DIRS : "$out/share" \ + --prefix XDG_DATA_DIRS : "$out/share/gsettings-schemas/${name}" \ + --prefix XDG_DATA_DIRS : "${gsettings-desktop-schemas}/share/gsettings-schemas/${gsettings-desktop-schemas.name}" \ + --prefix XDG_DATA_DIRS : "${hicolor-icon-theme}/share" \ + --prefix GI_TYPELIB_PATH : "${lib.makeSearchPath "lib/girepository-1.0" [ pango json-glib ]}" + done +''; +``` + +Fortunately, there is [`wrapGAppsHook`]{#ssec-gnome-hooks-wrapgappshook}. It works in conjunction with other setup hooks that populate environment variables, and it will then wrap all executables in `bin` and `libexec` directories using said variables. + +For convenience, it also adds `dconf.lib` for a GIO module implementing a GSettings backend using `dconf`, `gtk3` for GSettings schemas, and `librsvg` for GdkPixbuf loader to the closure. There is also [`wrapGAppsHook4`]{#ssec-gnome-hooks-wrapgappshook4}, which replaces GTK 3 with GTK 4. And in case you are packaging a program without a graphical interface, you might want to use [`wrapGAppsNoGuiHook`]{#ssec-gnome-hooks-wrapgappsnoguihook}, which runs the same script as `wrapGAppsHook` but does not bring `gtk3` and `librsvg` into the closure. + +- `wrapGAppsHook` itself will add the package’s `share` directory to `XDG_DATA_DIRS`. + +- []{#ssec-gnome-hooks-glib} `glib` setup hook will populate `GSETTINGS_SCHEMAS_PATH` and then `wrapGAppsHook` will prepend it to `XDG_DATA_DIRS`. + +- []{#ssec-gnome-hooks-gdk-pixbuf} `gdk-pixbuf` setup hook will populate `GDK_PIXBUF_MODULE_FILE` with the path to biggest `loaders.cache` file from the dependencies containing [GdkPixbuf loaders](#ssec-gnome-gdk-pixbuf-loaders). This works fine when there are only two packages containing loaders (`gdk-pixbuf` and e.g. `librsvg`) – it will choose the second one, reasonably expecting that it will be bigger since it describes extra loader in addition to the default ones. But when there are more than two loader packages, this logic will break. One possible solution would be constructing a custom cache file for each package containing a program like `services/x11/gdk-pixbuf.nix` NixOS module does. `wrapGAppsHook` copies the `GDK_PIXBUF_MODULE_FILE` environment variable into the produced wrapper. + +- []{#ssec-gnome-hooks-gtk-drop-icon-theme-cache} One of `gtk3`’s setup hooks will remove `icon-theme.cache` files from package’s icon theme directories to avoid conflicts. Icon theme packages should prevent this with `dontDropIconThemeCache = true;`. + +- []{#ssec-gnome-hooks-dconf} `dconf.lib` is a dependency of `wrapGAppsHook`, which then also adds it to the `GIO_EXTRA_MODULES` variable. + +- []{#ssec-gnome-hooks-hicolor-icon-theme} `hicolor-icon-theme`’s setup hook will add icon themes to `XDG_ICON_DIRS` which is prepended to `XDG_DATA_DIRS` by `wrapGAppsHook`. + +- []{#ssec-gnome-hooks-gobject-introspection} `gobject-introspection` setup hook populates `GI_TYPELIB_PATH` variable with `lib/girepository-1.0` directories of dependencies, which is then added to wrapper by `wrapGAppsHook`. It also adds `share` directories of dependencies to `XDG_DATA_DIRS`, which is intended to promote GIR files but it also [pollutes the closures](https://github.com/NixOS/nixpkgs/issues/32790) of packages using `wrapGAppsHook`. + + ::: {.warning} + The setup hook [currently](https://github.com/NixOS/nixpkgs/issues/56943) does not work in expressions with `strictDeps` enabled, like Python packages. In those cases, you will need to disable it with `strictDeps = false;`. + ::: + +- []{#ssec-gnome-hooks-gst-grl-plugins} Setup hooks of `gst_all_1.gstreamer` and `grilo` will populate the `GST_PLUGIN_SYSTEM_PATH_1_0` and `GRL_PLUGIN_PATH` variables, respectively, which will then be added to the wrapper by `wrapGAppsHook`. + +You can also pass additional arguments to `makeWrapper` using `gappsWrapperArgs` in `preFixup` hook: + +```nix +preFixup = '' + gappsWrapperArgs+=( + # Thumbnailers + --prefix XDG_DATA_DIRS : "${gdk-pixbuf}/share" + --prefix XDG_DATA_DIRS : "${librsvg}/share" + --prefix XDG_DATA_DIRS : "${shared-mime-info}/share" + ) +''; +``` + +## Updating GNOME packages {#ssec-gnome-updating} + +Most GNOME package offer [`updateScript`](#var-passthru-updateScript), it is therefore possible to update to latest source tarball by running `nix-shell maintainers/scripts/update.nix --argstr package gnome.nautilus` or even en masse with `nix-shell maintainers/scripts/update.nix --argstr path gnome`. Read the package’s `NEWS` file to see what changed. + +## Frequently encountered issues {#ssec-gnome-common-issues} + +#### `GLib-GIO-ERROR **: 06:04:50.903: No GSettings schemas are installed on the system` {#ssec-gnome-common-issues-no-schemas} + +There are no schemas available in `XDG_DATA_DIRS`. Temporarily add a random package containing schemas like `gsettings-desktop-schemas` to `buildInputs`. [`glib`](#ssec-gnome-hooks-glib) and [`wrapGAppsHook`](#ssec-gnome-hooks-wrapgappshook) setup hooks will take care of making the schemas available to application and you will see the actual missing schemas with the [next error](#ssec-gnome-common-issues-missing-schema). Or you can try looking through the source code for the actual schemas used. + +#### `GLib-GIO-ERROR **: 06:04:50.903: Settings schema ‘org.gnome.foo’ is not installed` {#ssec-gnome-common-issues-missing-schema} + +Package is missing some GSettings schemas. You can find out the package containing the schema with `nix-locate org.gnome.foo.gschema.xml` and let the hooks handle the wrapping as [above](#ssec-gnome-common-issues-no-schemas). + +#### When using `wrapGAppsHook` with special derivers you can end up with double wrapped binaries. {#ssec-gnome-common-issues-double-wrapped} + +This is because derivers like `python.pkgs.buildPythonApplication` or `qt5.mkDerivation` have setup-hooks automatically added that produce wrappers with makeWrapper. The simplest way to workaround that is to disable the `wrapGAppsHook` automatic wrapping with `dontWrapGApps = true;` and pass the arguments it intended to pass to makeWrapper to another. + +In the case of a Python application it could look like: + +```nix +python3.pkgs.buildPythonApplication { + pname = "gnome-music"; + version = "3.32.2"; + + nativeBuildInputs = [ + wrapGAppsHook + gobject-introspection + ... + ]; + + dontWrapGApps = true; + + # Arguments to be passed to `makeWrapper`, only used by buildPython* + preFixup = '' + makeWrapperArgs+=("''${gappsWrapperArgs[@]}") + ''; +} +``` + +And for a QT app like: + +```nix +mkDerivation { + pname = "calibre"; + version = "3.47.0"; + + nativeBuildInputs = [ + wrapGAppsHook + qmake + ... + ]; + + dontWrapGApps = true; + + # Arguments to be passed to `makeWrapper`, only used by qt5’s mkDerivation + preFixup = '' + qtWrapperArgs+=("''${gappsWrapperArgs[@]}") + ''; +} +``` + +#### I am packaging a project that cannot be wrapped, like a library or GNOME Shell extension. {#ssec-gnome-common-issues-unwrappable-package} + +You can rely on applications depending on the library setting the necessary environment variables but that is often easy to miss. Instead we recommend to patch the paths in the source code whenever possible. Here are some examples: + +- []{#ssec-gnome-common-issues-unwrappable-package-gnome-shell-ext} [Replacing a `GI_TYPELIB_PATH` in GNOME Shell extension](https://github.com/NixOS/nixpkgs/blob/7bb8f05f12ca3cff9da72b56caa2f7472d5732bc/pkgs/desktops/gnome-3/core/gnome-shell-extensions/default.nix#L21-L24) – we are using `substituteAll` to include the path to a typelib into a patch. + +- []{#ssec-gnome-common-issues-unwrappable-package-gsettings} The following examples are hardcoding GSettings schema paths. To get the schema paths we use the functions + + * `glib.getSchemaPath` Takes a nix package attribute as an argument. + + * `glib.makeSchemaPath` Takes a package output like `$out` and a derivation name. You should use this if the schemas you need to hardcode are in the same derivation. + + []{#ssec-gnome-common-issues-unwrappable-package-gsettings-vala} [Hard-coding GSettings schema path in Vala plug-in (dynamically loaded library)](https://github.com/NixOS/nixpkgs/blob/7bb8f05f12ca3cff9da72b56caa2f7472d5732bc/pkgs/desktops/pantheon/apps/elementary-files/default.nix#L78-L86) – here, `substituteAll` cannot be used since the schema comes from the same package preventing us from pass its path to the function, probably due to a [Nix bug](https://github.com/NixOS/nix/issues/1846). + + []{#ssec-gnome-common-issues-unwrappable-package-gsettings-c} [Hard-coding GSettings schema path in C library](https://github.com/NixOS/nixpkgs/blob/29c120c065d03b000224872251bed93932d42412/pkgs/development/libraries/glib-networking/default.nix#L31-L34) – nothing special other than using [Coccinelle patch](https://github.com/NixOS/nixpkgs/pull/67957#issuecomment-527717467) to generate the patch itself. + +#### I need to wrap a binary outside `bin` and `libexec` directories. {#ssec-gnome-common-issues-weird-location} + +You can manually trigger the wrapping with `wrapGApp` in `preFixup` phase. It takes a path to a program as a first argument; the remaining arguments are passed directly to [`wrapProgram`](#fun-wrapProgram) function. diff --git a/doc/languages-frameworks/go.section.md b/doc/languages-frameworks/go.section.md new file mode 100644 index 00000000000..411205d08e4 --- /dev/null +++ b/doc/languages-frameworks/go.section.md @@ -0,0 +1,145 @@ +# Go {#sec-language-go} + +## Go modules {#ssec-language-go} + +The function `buildGoModule` builds Go programs managed with Go modules. It builds a [Go Modules](https://github.com/golang/go/wiki/Modules) through a two phase build: + +- An intermediate fetcher derivation. This derivation will be used to fetch all of the dependencies of the Go module. +- A final derivation will use the output of the intermediate derivation to build the binaries and produce the final output. + +### Example for `buildGoModule` {#ex-buildGoModule} + +In the following is an example expression using `buildGoModule`, the following arguments are of special significance to the function: + +- `vendorSha256`: is the hash of the output of the intermediate fetcher derivation. `vendorSha256` can also take `null` as an input. When `null` is used as a value, rather than fetching the dependencies and vendoring them, we use the vendoring included within the source repo. If you'd like to not have to update this field on dependency changes, run `go mod vendor` in your source repo and set `vendorSha256 = null;` +- `proxyVendor`: Fetches (go mod download) and proxies the vendor directory. This is useful if your code depends on c code and go mod tidy does not include the needed sources to build or if any dependency has case-insensitive conflicts which will produce platform dependant `vendorSha256` checksums. + +```nix +pet = buildGoModule rec { + pname = "pet"; + version = "0.3.4"; + + src = fetchFromGitHub { + owner = "knqyf263"; + repo = "pet"; + rev = "v${version}"; + sha256 = "0m2fzpqxk7hrbxsgqplkg7h2p7gv6s1miymv3gvw0cz039skag0s"; + }; + + vendorSha256 = "1879j77k96684wi554rkjxydrj8g3hpp0kvxz03sd8dmwr3lh83j"; + + meta = with lib; { + description = "Simple command-line snippet manager, written in Go"; + homepage = "https://github.com/knqyf263/pet"; + license = licenses.mit; + maintainers = with maintainers; [ kalbasit ]; + }; +} +``` + +## `buildGoPackage` (legacy) {#ssec-go-legacy} + +The function `buildGoPackage` builds legacy Go programs, not supporting Go modules. + +### Example for `buildGoPackage` {#example-for-buildgopackage} + +In the following is an example expression using buildGoPackage, the following arguments are of special significance to the function: + +- `goPackagePath` specifies the package's canonical Go import path. +- `goDeps` is where the Go dependencies of a Go program are listed as a list of package source identified by Go import path. It could be imported as a separate `deps.nix` file for readability. The dependency data structure is described below. + +```nix +deis = buildGoPackage rec { + pname = "deis"; + version = "1.13.0"; + + goPackagePath = "github.com/deis/deis"; + + src = fetchFromGitHub { + owner = "deis"; + repo = "deis"; + rev = "v${version}"; + sha256 = "1qv9lxqx7m18029lj8cw3k7jngvxs4iciwrypdy0gd2nnghc68sw"; + }; + + goDeps = ./deps.nix; +} +``` + +The `goDeps` attribute can be imported from a separate `nix` file that defines which Go libraries are needed and should be included in `GOPATH` for `buildPhase`: + +```nix +# deps.nix +[ # goDeps is a list of Go dependencies. + { + # goPackagePath specifies Go package import path. + goPackagePath = "gopkg.in/yaml.v2"; + fetch = { + # `fetch type` that needs to be used to get package source. + # If `git` is used there should be `url`, `rev` and `sha256` defined next to it. + type = "git"; + url = "https://gopkg.in/yaml.v2"; + rev = "a83829b6f1293c91addabc89d0571c246397bbf4"; + sha256 = "1m4dsmk90sbi17571h6pld44zxz7jc4lrnl4f27dpd1l8g5xvjhh"; + }; + } + { + goPackagePath = "github.com/docopt/docopt-go"; + fetch = { + type = "git"; + url = "https://github.com/docopt/docopt-go"; + rev = "784ddc588536785e7299f7272f39101f7faccc3f"; + sha256 = "0wwz48jl9fvl1iknvn9dqr4gfy1qs03gxaikrxxp9gry6773v3sj"; + }; + } +] +``` + +To extract dependency information from a Go package in automated way use [go2nix](https://github.com/kamilchm/go2nix). It can produce complete derivation and `goDeps` file for Go programs. + +You may use Go packages installed into the active Nix profiles by adding the following to your ~/.bashrc: + +```bash +for p in $NIX_PROFILES; do + GOPATH="$p/share/go:$GOPATH" +done +``` + +## Attributes used by the builders {#ssec-go-common-attributes} + +Both `buildGoModule` and `buildGoPackage` can be tweaked to behave slightly differently, if the following attributes are used: + +### `ldflags` {#var-go-ldflags} + +Arguments to pass to the Go linker tool via the `-ldflags` argument of `go build`. The most common use case for this argument is to make the resulting executable aware of its own version. For example: + +```nix + ldflags = [ + "-s" "-w" + "-X main.Version=${version}" + "-X main.Commit=${version}" + ]; +``` + +### `tags` {#var-go-tags} + +Arguments to pass to the Go via the `-tags` argument of `go build`. For example: + +```nix + tags = [ + "production" + "sqlite" + ]; +``` + +```nix + tags = [ "production" ] ++ lib.optionals withSqlite [ "sqlite" ]; +``` + +### `deleteVendor` {#var-go-deleteVendor} + +Removes the pre-existing vendor directory. This should only be used if the dependencies included in the vendor folder are broken or incomplete. + +### `subPackages` {#var-go-subPackages} + +Limits the builder from building child packages that have not been listed. If `subPackages` is not specified, all child packages will be built. diff --git a/doc/languages-frameworks/haskell.section.md b/doc/languages-frameworks/haskell.section.md new file mode 100644 index 00000000000..1fda505a225 --- /dev/null +++ b/doc/languages-frameworks/haskell.section.md @@ -0,0 +1,7 @@ +# Haskell {#haskell} + +The documentation for the Haskell infrastructure is published at +<https://haskell4nix.readthedocs.io/>. The source code for that +site lives in the `doc/` sub-directory of the +[`cabal2nix` Git repository](https://github.com/NixOS/cabal2nix) +and changes can be submitted there. diff --git a/doc/languages-frameworks/hy.section.md b/doc/languages-frameworks/hy.section.md new file mode 100644 index 00000000000..a851ff24dfc --- /dev/null +++ b/doc/languages-frameworks/hy.section.md @@ -0,0 +1,31 @@ +# Hy {#sec-language-hy} + +## Installation {#ssec-hy-installation} + +### Installation without packages {#installation-without-packages} + +You can install `hy` via nix-env or by adding it to `configuration.nix` by reffering to it as a `hy` attribute. This kind of installation adds `hy` to your environment and it succesfully works with `python3`. + +::: {.caution} +Packages that are installed with your python derivation, are not accesible by `hy` this way. +::: + +### Installation with packages {#installation-with-packages} + +Creating `hy` derivation with custom `python` packages is really simple and similar to the way that python does it. Attribute `hy` provides function `withPackages` that creates custom `hy` derivation with specified packages. + +For example if you want to create shell with `matplotlib` and `numpy`, you can do it like so: + +```ShellSession +$ nix-shell -p "hy.withPackages (ps: with ps; [ numpy matplotlib ])" +``` + +Or if you want to extend your `configuration.nix`: +```nix +{ # ... + + environment.systemPackages = with pkgs; [ + (hy.withPackages (py-packages: with py-packages; [ numpy matplotlib ])) + ]; +} +``` diff --git a/doc/languages-frameworks/idris.section.md b/doc/languages-frameworks/idris.section.md new file mode 100644 index 00000000000..19146844cff --- /dev/null +++ b/doc/languages-frameworks/idris.section.md @@ -0,0 +1,143 @@ +# Idris {#idris} + +## Installing Idris {#installing-idris} + +The easiest way to get a working idris version is to install the `idris` attribute: + +```ShellSession +$ nix-env -f "<nixpkgs>" -iA idris +``` + +This however only provides the `prelude` and `base` libraries. To install idris with additional libraries, you can use the `idrisPackages.with-packages` function, e.g. in an overlay in `~/.config/nixpkgs/overlays/my-idris.nix`: + +```nix +self: super: { + myIdris = with self.idrisPackages; with-packages [ contrib pruviloj ]; +} +``` + +And then: + +```ShellSession +$ # On NixOS +$ nix-env -iA nixos.myIdris +$ # On non-NixOS +$ nix-env -iA nixpkgs.myIdris +``` + +To see all available Idris packages: + +```ShellSession +$ # On NixOS +$ nix-env -qaPA nixos.idrisPackages +$ # On non-NixOS +$ nix-env -qaPA nixpkgs.idrisPackages +``` + +Similarly, entering a `nix-shell`: + +```ShellSession +$ nix-shell -p 'idrisPackages.with-packages (with idrisPackages; [ contrib pruviloj ])' +``` + +## Starting Idris with library support {#starting-idris-with-library-support} + +To have access to these libraries in idris, call it with an argument `-p <library name>` for each library: + +```ShellSession +$ nix-shell -p 'idrisPackages.with-packages (with idrisPackages; [ contrib pruviloj ])' +[nix-shell:~]$ idris -p contrib -p pruviloj +``` + +A listing of all available packages the Idris binary has access to is available via `--listlibs`: + +```ShellSession +$ idris --listlibs +00prelude-idx.ibc +pruviloj +base +contrib +prelude +00pruviloj-idx.ibc +00base-idx.ibc +00contrib-idx.ibc +``` + +## Building an Idris project with Nix {#building-an-idris-project-with-nix} + +As an example of how a Nix expression for an Idris package can be created, here is the one for `idrisPackages.yaml`: + +```nix +{ lib +, build-idris-package +, fetchFromGitHub +, contrib +, lightyear +}: +build-idris-package { + name = "yaml"; + version = "2018-01-25"; + + # This is the .ipkg file that should be built, defaults to the package name + # In this case it should build `Yaml.ipkg` instead of `yaml.ipkg` + # This is only necessary because the yaml packages ipkg file is + # different from its package name here. + ipkgName = "Yaml"; + # Idris dependencies to provide for the build + idrisDeps = [ contrib lightyear ]; + + src = fetchFromGitHub { + owner = "Heather"; + repo = "Idris.Yaml"; + rev = "5afa51ffc839844862b8316faba3bafa15656db4"; + sha256 = "1g4pi0swmg214kndj85hj50ccmckni7piprsxfdzdfhg87s0avw7"; + }; + + meta = with lib; { + description = "Idris YAML lib"; + homepage = "https://github.com/Heather/Idris.Yaml"; + license = licenses.mit; + maintainers = [ maintainers.brainrape ]; + }; +} +``` + +Assuming this file is saved as `yaml.nix`, it's buildable using + +```ShellSession +$ nix-build -E '(import <nixpkgs> {}).idrisPackages.callPackage ./yaml.nix {}' +``` + +Or it's possible to use + +```nix +with import <nixpkgs> {}; + +{ + yaml = idrisPackages.callPackage ./yaml.nix {}; +} +``` + +in another file (say `default.nix`) to be able to build it with + +```ShellSession +$ nix-build -A yaml +``` + +## Passing options to `idris` commands {#passing-options-to-idris-commands} + +The `build-idris-package` function provides also optional input values to set additional options for the used `idris` commands. + +Specifically, you can set `idrisBuildOptions`, `idrisTestOptions`, `idrisInstallOptions` and `idrisDocOptions` to provide additional options to the `idris` command respectively when building, testing, installing and generating docs for your package. + +For example you could set + +```nix +build-idris-package { + idrisBuildOptions = [ "--log" "1" "--verbose" ] + + ... +} +``` + +to require verbose output during `idris` build phase. diff --git a/doc/languages-frameworks/index.xml b/doc/languages-frameworks/index.xml new file mode 100644 index 00000000000..f221693e764 --- /dev/null +++ b/doc/languages-frameworks/index.xml @@ -0,0 +1,40 @@ +<chapter xmlns="http://docbook.org/ns/docbook" + xmlns:xi="http://www.w3.org/2001/XInclude" + xml:id="chap-language-support"> + <title>Languages and frameworks</title> + <para> + The <link linkend="chap-stdenv">standard build environment</link> makes it easy to build typical Autotools-based packages with very little code. Any other kind of package can be accomodated by overriding the appropriate phases of <literal>stdenv</literal>. However, there are specialised functions in Nixpkgs to easily build packages for other programming languages, such as Perl or Haskell. These are described in this chapter. + </para> + <xi:include href="agda.section.xml" /> + <xi:include href="android.section.xml" /> + <xi:include href="beam.section.xml" /> + <xi:include href="bower.section.xml" /> + <xi:include href="coq.section.xml" /> + <xi:include href="crystal.section.xml" /> + <xi:include href="dhall.section.xml" /> + <xi:include href="dotnet.section.xml" /> + <xi:include href="emscripten.section.xml" /> + <xi:include href="gnome.section.xml" /> + <xi:include href="go.section.xml" /> + <xi:include href="haskell.section.xml" /> + <xi:include href="hy.section.xml" /> + <xi:include href="idris.section.xml" /> + <xi:include href="ios.section.xml" /> + <xi:include href="java.section.xml" /> + <xi:include href="javascript.section.xml" /> + <xi:include href="lua.section.xml" /> + <xi:include href="maven.section.xml" /> + <xi:include href="nim.section.xml" /> + <xi:include href="ocaml.section.xml" /> + <xi:include href="octave.section.xml" /> + <xi:include href="perl.section.xml" /> + <xi:include href="php.section.xml" /> + <xi:include href="python.section.xml" /> + <xi:include href="qt.section.xml" /> + <xi:include href="r.section.xml" /> + <xi:include href="ruby.section.xml" /> + <xi:include href="rust.section.xml" /> + <xi:include href="texlive.section.xml" /> + <xi:include href="titanium.section.xml" /> + <xi:include href="vim.section.xml" /> +</chapter> diff --git a/doc/languages-frameworks/ios.section.md b/doc/languages-frameworks/ios.section.md new file mode 100644 index 00000000000..04b013be12e --- /dev/null +++ b/doc/languages-frameworks/ios.section.md @@ -0,0 +1,225 @@ +# iOS {#ios} + +This component is basically a wrapper/workaround that makes it possible to +expose an Xcode installation as a Nix package by means of symlinking to the +relevant executables on the host system. + +Since Xcode can't be packaged with Nix, nor we can publish it as a Nix package +(because of its license) this is basically the only integration strategy +making it possible to do iOS application builds that integrate with other +components of the Nix ecosystem + +The primary objective of this project is to use the Nix expression language to +specify how iOS apps can be built from source code, and to automatically spawn +iOS simulator instances for testing. + +This component also makes it possible to use [Hydra](https://nixos.org/hydra), +the Nix-based continuous integration server to regularly build iOS apps and to +do wireless ad-hoc installations of enterprise IPAs on iOS devices through +Hydra. + +The Xcode build environment implements a number of features. + +## Deploying a proxy component wrapper exposing Xcode {#deploying-a-proxy-component-wrapper-exposing-xcode} + +The first use case is deploying a Nix package that provides symlinks to the Xcode +installation on the host system. This package can be used as a build input to +any build function implemented in the Nix expression language that requires +Xcode. + +```nix +let + pkgs = import <nixpkgs> {}; + + xcodeenv = import ./xcodeenv { + inherit (pkgs) stdenv; + }; +in +xcodeenv.composeXcodeWrapper { + version = "9.2"; + xcodeBaseDir = "/Applications/Xcode.app"; +} +``` + +By deploying the above expression with `nix-build` and inspecting its content +you will notice that several Xcode-related executables are exposed as a Nix +package: + +```bash +$ ls result/bin +lrwxr-xr-x 1 sander staff 94 1 jan 1970 Simulator -> /Applications/Xcode.app/Contents/Developer/Applications/Simulator.app/Contents/MacOS/Simulator +lrwxr-xr-x 1 sander staff 17 1 jan 1970 codesign -> /usr/bin/codesign +lrwxr-xr-x 1 sander staff 17 1 jan 1970 security -> /usr/bin/security +lrwxr-xr-x 1 sander staff 21 1 jan 1970 xcode-select -> /usr/bin/xcode-select +lrwxr-xr-x 1 sander staff 61 1 jan 1970 xcodebuild -> /Applications/Xcode.app/Contents/Developer/usr/bin/xcodebuild +lrwxr-xr-x 1 sander staff 14 1 jan 1970 xcrun -> /usr/bin/xcrun +``` + +## Building an iOS application {#building-an-ios-application} + +We can build an iOS app executable for the simulator, or an IPA/xcarchive file +for release purposes, e.g. ad-hoc, enterprise or store installations, by +executing the `xcodeenv.buildApp {}` function: + +```nix +let + pkgs = import <nixpkgs> {}; + + xcodeenv = import ./xcodeenv { + inherit (pkgs) stdenv; + }; +in +xcodeenv.buildApp { + name = "MyApp"; + src = ./myappsources; + sdkVersion = "11.2"; + + target = null; # Corresponds to the name of the app by default + configuration = null; # Release for release builds, Debug for debug builds + scheme = null; # -scheme will correspond to the app name by default + sdk = null; # null will set it to 'iphonesimulator` for simulator builds or `iphoneos` to real builds + xcodeFlags = ""; + + release = true; + certificateFile = ./mycertificate.p12; + certificatePassword = "secret"; + provisioningProfile = ./myprovisioning.profile; + signMethod = "ad-hoc"; # 'enterprise' or 'store' + generateIPA = true; + generateXCArchive = false; + + enableWirelessDistribution = true; + installURL = "/installipa.php"; + bundleId = "mycompany.myapp"; + appVersion = "1.0"; + + # Supports all xcodewrapper parameters as well + xcodeBaseDir = "/Applications/Xcode.app"; +} +``` + +The above function takes a variety of parameters: + +* The `name` and `src` parameters are mandatory and specify the name of the app + and the location where the source code resides +* `sdkVersion` specifies which version of the iOS SDK to use. + +It also possile to adjust the `xcodebuild` parameters. This is only needed in +rare circumstances. In most cases the default values should suffice: + +* Specifies which `xcodebuild` target to build. By default it takes the target + that has the same name as the app. +* The `configuration` parameter can be overridden if desired. By default, it + will do a debug build for the simulator and a release build for real devices. +* The `scheme` parameter specifies which `-scheme` parameter to propagate to + `xcodebuild`. By default, it corresponds to the app name. +* The `sdk` parameter specifies which SDK to use. By default, it picks + `iphonesimulator` for simulator builds and `iphoneos` for release builds. +* The `xcodeFlags` parameter specifies arbitrary command line parameters that + should be propagated to `xcodebuild`. + +By default, builds are carried out for the iOS simulator. To do release builds +(builds for real iOS devices), you must set the `release` parameter to `true`. +In addition, you need to set the following parameters: + +* `certificateFile` refers to a P12 certificate file. +* `certificatePassword` specifies the password of the P12 certificate. +* `provisioningProfile` refers to the provision profile needed to sign the app +* `signMethod` should refer to `ad-hoc` for signing the app with an ad-hoc + certificate, `enterprise` for enterprise certificates and `app-store` for App + store certificates. +* `generateIPA` specifies that we want to produce an IPA file (this is probably + what you want) +* `generateXCArchive` specifies thet we want to produce an xcarchive file. + +When building IPA files on Hydra and when it is desired to allow iOS devices to +install IPAs by browsing to the Hydra build products page, you can enable the +`enableWirelessDistribution` parameter. + +When enabled, you need to configure the following options: + +* The `installURL` parameter refers to the URL of a PHP script that composes the + `itms-services://` URL allowing iOS devices to install the IPA file. +* `bundleId` refers to the bundle ID value of the app +* `appVersion` refers to the app's version number + +To use wireless adhoc distributions, you must also install the corresponding +PHP script on a web server (see section: 'Installing the PHP script for wireless +ad hoc installations from Hydra' for more information). + +In addition to the build parameters, you can also specify any parameters that +the `xcodeenv.composeXcodeWrapper {}` function takes. For example, the +`xcodeBaseDir` parameter can be overridden to refer to a different Xcode +version. + +## Spawning simulator instances {#spawning-simulator-instances} + +In addition to building iOS apps, we can also automatically spawn simulator +instances: + +```nix +let + pkgs = import <nixpkgs> {}; + + xcodeenv = import ./xcodeenv { + inherit (pkgs) stdenv; + }; +in +xcode.simulateApp { + name = "simulate"; + + # Supports all xcodewrapper parameters as well + xcodeBaseDir = "/Applications/Xcode.app"; +} +``` + +The above expression produces a script that starts the simulator from the +provided Xcode installation. The script can be started as follows: + +```bash +./result/bin/run-test-simulator +``` + +By default, the script will show an overview of UDID for all available simulator +instances and asks you to pick one. You can also provide a UDID as a +command-line parameter to launch an instance automatically: + +```bash +./result/bin/run-test-simulator 5C93129D-CF39-4B1A-955F-15180C3BD4B8 +``` + +You can also extend the simulator script to automatically deploy and launch an +app in the requested simulator instance: + +```nix +let + pkgs = import <nixpkgs> {}; + + xcodeenv = import ./xcodeenv { + inherit (pkgs) stdenv; + }; +in +xcode.simulateApp { + name = "simulate"; + bundleId = "mycompany.myapp"; + app = xcode.buildApp { + # ... + }; + + # Supports all xcodewrapper parameters as well + xcodeBaseDir = "/Applications/Xcode.app"; +} +``` + +By providing the result of an `xcode.buildApp {}` function and configuring the +app bundle id, the app gets deployed automatically and started. + +## Troubleshooting {#troubleshooting} + +In some rare cases, it may happen that after a failure, changes are not picked +up. Most likely, this is caused by a derived data cache that Xcode maintains. +To wipe it you can run: + +```bash +$ rm -rf ~/Library/Developer/Xcode/DerivedData +``` diff --git a/doc/languages-frameworks/java.section.md b/doc/languages-frameworks/java.section.md new file mode 100644 index 00000000000..371bdf6323f --- /dev/null +++ b/doc/languages-frameworks/java.section.md @@ -0,0 +1,100 @@ +# Java {#sec-language-java} + +Ant-based Java packages are typically built from source as follows: + +```nix +stdenv.mkDerivation { + name = "..."; + src = fetchurl { ... }; + + nativeBuildInputs = [ jdk ant ]; + + buildPhase = "ant"; +} +``` + +Note that `jdk` is an alias for the OpenJDK (self-built where available, +or pre-built via Zulu). Platforms with OpenJDK not (yet) in Nixpkgs +(`Aarch32`, `Aarch64`) point to the (unfree) `oraclejdk`. + +JAR files that are intended to be used by other packages should be +installed in `$out/share/java`. JDKs have a stdenv setup hook that add +any JARs in the `share/java` directories of the build inputs to the +`CLASSPATH` environment variable. For instance, if the package `libfoo` +installs a JAR named `foo.jar` in its `share/java` directory, and +another package declares the attribute + +```nix +buildInputs = [ libfoo ]; +nativeBuildInputs = [ jdk ]; +``` + +then `CLASSPATH` will be set to +`/nix/store/...-libfoo/share/java/foo.jar`. + +Private JARs should be installed in a location like +`$out/share/package-name`. + +If your Java package provides a program, you need to generate a wrapper +script to run it using a JRE. You can use `makeWrapper` for this: + +```nix +nativeBuildInputs = [ makeWrapper ]; + +installPhase = '' + mkdir -p $out/bin + makeWrapper ${jre}/bin/java $out/bin/foo \ + --add-flags "-cp $out/share/java/foo.jar org.foo.Main" +''; +``` + +Since the introduction of the Java Platform Module System in Java 9, +Java distributions typically no longer ship with a general-purpose JRE: +instead, they allow generating a JRE with only the modules required for +your application(s). Because we can't predict what modules will be +needed on a general-purpose system, the default jre package is the full +JDK. When building a minimal system/image, you can override the +`modules` parameter on `jre_minimal` to build a JRE with only the +modules relevant for you: + +```nix +let + my_jre = pkgs.jre_minimal.override { + modules = [ + # The modules used by 'something' and 'other' combined: + "java.base" + "java.logging" + ]; + }; + something = (pkgs.something.override { jre = my_jre; }); + other = (pkgs.other.override { jre = my_jre; }); +in + ... +``` + +You can also specify what JDK your JRE should be based on, for example +selecting a 'headless' build to avoid including a link to GTK+: + +```nix +my_jre = pkgs.jre_minimal.override { + jdk = jdk11_headless; +}; +``` + +Note all JDKs passthru `home`, so if your application requires +environment variables like `JAVA_HOME` being set, that can be done in a +generic fashion with the `--set` argument of `makeWrapper`: + +```bash +--set JAVA_HOME ${jdk.home} +``` + +It is possible to use a different Java compiler than `javac` from the +OpenJDK. For instance, to use the GNU Java Compiler: + +```nix +nativeBuildInputs = [ gcj ant ]; +``` + +Here, Ant will automatically use `gij` (the GNU Java Runtime) instead of +the OpenJRE. diff --git a/doc/languages-frameworks/javascript.section.md b/doc/languages-frameworks/javascript.section.md new file mode 100644 index 00000000000..bf5742d6855 --- /dev/null +++ b/doc/languages-frameworks/javascript.section.md @@ -0,0 +1,256 @@ +# Javascript {#language-javascript} + +## Introduction {#javascript-introduction} + +This contains instructions on how to package javascript applications. + +The various tools available will be listed in the [tools-overview](#javascript-tools-overview). Some general principles for packaging will follow. Finally some tool specific instructions will be given. + +## Getting unstuck / finding code examples + +If you find you are lacking inspiration for packing javascript applications, the links below might prove useful. +Searching online for prior art can be helpful if you are running into solved problems. + +### Github + +- Searching Nix files for `mkYarnPackage`: <https://github.com/search?q=mkYarnPackage+language%3ANix&type=code> + +- Searching just `flake.nix` files for `mkYarnPackage`: <https://github.com/search?q=mkYarnPackage+filename%3Aflake.nix&type=code> + +### Gitlab + +- Searching Nix files for `mkYarnPackage`: <https://gitlab.com/search?scope=blobs&search=mkYarnPackage+extension%3Anix> + +- Searching just `flake.nix` files for `mkYarnPackage`: <https://gitlab.com/search?scope=blobs&search=mkYarnPackage+filename%3Aflake.nix> + +## Tools overview {#javascript-tools-overview} + +## General principles {#javascript-general-principles} + +The following principles are given in order of importance with potential exceptions. + +### Try to use the same node version used upstream {#javascript-upstream-node-version} + +It is often not documented which node version is used upstream, but if it is, try to use the same version when packaging. + +This can be a problem if upstream is using the latest and greatest and you are trying to use an earlier version of node. Some cryptic errors regarding V8 may appear. + +An exception to this: + +### Try to respect the package manager originally used by upstream (and use the upstream lock file) {#javascript-upstream-package-manager} + +A lock file (package-lock.json, yarn.lock...) is supposed to make reproducible installations of node_modules for each tool. + +Guidelines of package managers, recommend to commit those lock files to the repos. If a particular lock file is present, it is a strong indication of which package manager is used upstream. + +It's better to try to use a nix tool that understand the lock file. Using a different tool might give you hard to understand error because different packages have been installed. An example of problems that could arise can be found [here](https://github.com/NixOS/nixpkgs/pull/126629). Upstream uses npm, but this is an attempt to package it with yarn2nix (that uses yarn.lock) + +Using a different tool forces to commit a lock file to the repository. Those files are fairly large, so when packaging for nixpkgs, this approach does not scale well. + +Exceptions to this rule are: + +- when you encounter one of the bugs from a nix tool. In each of the tool specific instructions, known problems will be detailed. If you have a problem with a particular tool, then it's best to try another tool, even if this means you will have to recreate a lock file and commit it to nixpkgs. In general yarn2nix has less known problems and so a simple search in nixpkgs will reveal many yarn.lock files committed +- Some lock files contain particular version of a package that has been pulled off npm for some reason. In that case, you can recreate upstream lock (by removing the original and `npm install`, `yarn`, ...) and commit this to nixpkgs. +- The only tool that supports workspaces (a feature of npm that helps manage sub-directories with different package.json from a single top level package.json) is yarn2nix. If upstream has workspaces you should try yarn2nix. + +### Try to use upstream package.json {#javascript-upstream-package-json} + +Exceptions to this rule are + +- Sometimes the upstream repo assumes some dependencies be installed globally. In that case you can add them manually to the upstream package.json (`yarn add xxx` or `npm install xxx`, ...). Dependencies that are installed locally can be executed with `npx` for cli tools. (e.g. `npx postcss ...`, this is how you can call those dependencies in the phases). +- Sometimes there is a version conflict between some dependency requirements. In that case you can fix a version (by removing the `^`). +- Sometimes the script defined in the package.json does not work as is. Some scripts for example use cli tools that might not be available, or cd in directory with a different package.json (for workspaces notably). In that case, it's perfectly fine to look at what the particular script is doing and break this down in the phases. In the build script you can see `build:*` calling in turns several other build scripts like `build:ui` or `build:server`. If one of those fails, you can try to separate those into: + +```Shell +yarn build:ui +yarn build:server +# OR +npm run build:ui +npm run build:server +``` + +when you need to override a package.json. It's nice to use the one from the upstream src and do some explicit override. Here is an example. + +```nix +patchedPackageJSON = final.runCommand "package.json" { } '' + ${jq}/bin/jq '.version = "0.4.0" | + .devDependencies."@jsdoc/cli" = "^0.2.5" + ${sonar-src}/package.json > $out +''; +``` + +you will still need to commit the modified version of the lock files, but at least the overrides are explicit for everyone to see. + +### Using node_modules directly {#javascript-using-node_modules} + +each tool has an abstraction to just build the node_modules (dependencies) directory. you can always use the stdenv.mkDerivation with the node_modules to build the package (symlink the node_modules directory and then use the package build command). the node_modules abstraction can be also used to build some web framework frontends. For an example of this see how [plausible](https://github.com/NixOS/nixpkgs/blob/master/pkgs/servers/web-apps/plausible/default.nix) is built. mkYarnModules to make the derivation containing node_modules. Then when building the frontend you can just symlink the node_modules directory + +## javascript packages inside nixpkgs {#javascript-packages-nixpkgs} + +The `pkgs/development/node-packages` folder contains a generated collection of +[NPM packages](https://npmjs.com/) that can be installed with the Nix package +manager. + +As a rule of thumb, the package set should only provide _end user_ software +packages, such as command-line utilities. Libraries should only be added to the +package set if there is a non-NPM package that requires it. + +When it is desired to use NPM libraries in a development project, use the +`node2nix` generator directly on the `package.json` configuration file of the +project. + +The package set provides support for the official stable Node.js versions. +The latest stable LTS release in `nodePackages`, as well as the latest stable +Current release in `nodePackages_latest`. + +If your package uses native addons, you need to examine what kind of native +build system it uses. Here are some examples: + +- `node-gyp` +- `node-gyp-builder` +- `node-pre-gyp` + +After you have identified the correct system, you need to override your package +expression while adding in build system as a build input. For example, `dat` +requires `node-gyp-build`, so [we override](https://github.com/NixOS/nixpkgs/blob/32f5e5da4a1b3f0595527f5195ac3a91451e9b56/pkgs/development/node-packages/default.nix#L37-L40) its expression in [`default.nix`](https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/node-packages/default.nix): + +```nix + dat = super.dat.override { + buildInputs = [ self.node-gyp-build pkgs.libtool pkgs.autoconf pkgs.automake ]; + meta.broken = since "12"; + }; +``` + +To add a package from NPM to nixpkgs: + +1. Modify `pkgs/development/node-packages/node-packages.json` to add, update + or remove package entries to have it included in `nodePackages` and + `nodePackages_latest`. +2. Run the script: `cd pkgs/development/node-packages && ./generate.sh`. +3. Build your new package to test your changes: + `cd /path/to/nixpkgs && nix-build -A nodePackages.<new-or-updated-package>`. + To build against the latest stable Current Node.js version (e.g. 14.x): + `nix-build -A nodePackages_latest.<new-or-updated-package>` +4. Add and commit all modified and generated files. + +For more information about the generation process, consult the +[README.md](https://github.com/svanderburg/node2nix) file of the `node2nix` +tool. + +## Tool specific instructions {#javascript-tool-specific} + +### node2nix {#javascript-node2nix} + +#### Preparation {#javascript-node2nix-preparation} + +you will need to generate a nix expression for the dependencies + +- don't forget the `-l package-lock.json` if there is a lock file +- Most probably you will need the `--development` to include the `devDependencies` + +so the command will most likely be +`node2nix --development -l package-lock.json` + +[link to the doc in the repo](https://github.com/svanderburg/node2nix) + +#### Pitfalls {#javascript-node2nix-pitfalls} + +- if upstream package.json does not have a "version" attribute, node2nix will crash. You will need to add it like shown in [the package.json section](#javascript-upstream-package-json) +- node2nix has some [bugs](https://github.com/svanderburg/node2nix/issues/238). related to working with lock files from npm distributed with nodejs-16_x +- node2nix does not like missing packages from npm. If you see something like `Cannot resolve version: vue-loader-v16@undefined` then you might want to try another tool. The package might have been pulled off of npm. + +### yarn2nix {#javascript-yarn2nix} + +#### Preparation {#javascript-yarn2nix-preparation} + +you will need at least a yarn.lock and yarn.nix file + +- generate a yarn.lock in upstream if it is not already there +- `yarn2nix > yarn.nix` will generate the dependencies in a nix format + +#### mkYarnPackage {#javascript-yarn2nix-mkYarnPackage} + +this will by default try to generate a binary. For package only generating static assets (Svelte, Vue, React...), you will need to explicitly override the build step with your instructions. It's important to use the `--offline` flag. For example if you script is `"build": "something"` in package.json use + +```nix +buildPhase = '' + yarn build --offline +''; +``` + +The dist phase is also trying to build a binary, the only way to override it is with + +```nix +distPhase = "true"; +``` + +the configure phase can sometimes fail because it tries to be too clever. +One common override is + +```nix +configurePhase = "ln -s $node_modules node_modules"; +``` + +#### mkYarnModules {#javascript-yarn2nix-mkYarnModules} + +this will generate a derivation including the node_modules. If you have to build a derivation for an integrated web framework (rails, phoenix..), this is probably the easiest way. [Plausible](https://github.com/NixOS/nixpkgs/blob/master/pkgs/servers/web-apps/plausible/default.nix#L39) offers a good example of how to do this. + +#### Overriding dependency behavior + +In the `mkYarnPackage` record the property `pkgConfig` can be used to override packages when you encounter problems building. + +For instance, say your package is throwing errors when trying to invoke node-sass: `ENOENT: no such file or directory, scandir '/build/source/node_modules/node-sass/vendor'` + +To fix this we will specify different versions of build inputs to use, as well as some post install steps to get the software built the way we want: + +```nix +mkYarnPackage rec { + pkgConfig = { + node-sass = { + buildInputs = with final;[ python libsass pkg-config ]; + postInstall = '' + LIBSASS_EXT=auto yarn --offline run build + rm build/config.gypi + ''; + }; + }; +} +``` + +#### Pitfalls {#javascript-yarn2nix-pitfalls} + +- if version is missing from upstream package.json, yarn will silently install nothing. In that case, you will need to override package.json as shown in the [package.json section](#javascript-upstream-package-json) + +- having trouble with node-gyp? Try adding these lines to the `yarnPreBuild` steps: + + ```nix + yarnPreBuild = '' + mkdir -p $HOME/.node-gyp/${nodejs.version} + echo 9 > $HOME/.node-gyp/${nodejs.version}/installVersion + ln -sfv ${nodejs}/include $HOME/.node-gyp/${nodejs.version} + export npm_config_nodedir=${nodejs} + ''; + ``` + + - The `echo 9` steps comes from this answer: <https://stackoverflow.com/a/49139496> + - Exporting the headers in `npm_config_nodedir` comes from this issue: <https://github.com/nodejs/node-gyp/issues/1191#issuecomment-301243919> + +## Outside of nixpkgs {#javascript-outside-nixpkgs} + +There are some other options available that can't be used inside nixpkgs. Those other options are written in nix. Importing them in nixpkgs will require moving the source code into nixpkgs. Using [Import From Derivation](https://nixos.wiki/wiki/Import_From_Derivation) is not allowed in hydra at present. If you are packaging something outside nixpkgs, those can be considered + +### npmlock2nix {#javascript-npmlock2nix} + +[npmlock2nix](https://github.com/nix-community/npmlock2nix) aims at building node_modules without code generation. It hasn't reached v1 yet, the api might be subject to change. + +#### Pitfalls {#javascript-npmlock2nix-pitfalls} + +- there are some [problems with npm v7](https://github.com/tweag/npmlock2nix/issues/45). + +### nix-npm-buildpackage {#javascript-nix-npm-buildpackage} + +[nix-npm-buildpackage](https://github.com/serokell/nix-npm-buildpackage) aims at building node_modules without code generation. It hasn't reached v1 yet, the api might change. It supports both package-lock.json and yarn.lock. + +#### Pitfalls {#javascript-nix-npm-buildpackage-pitfalls} + +- there are some [problems with npm v7](https://github.com/serokell/nix-npm-buildpackage/issues/33). diff --git a/doc/languages-frameworks/lua.section.md b/doc/languages-frameworks/lua.section.md new file mode 100644 index 00000000000..17b80f07d3e --- /dev/null +++ b/doc/languages-frameworks/lua.section.md @@ -0,0 +1,253 @@ +# User’s Guide to Lua Infrastructure {#users-guide-to-lua-infrastructure} + +## Using Lua {#using-lua} + +### Overview of Lua {#overview-of-lua} + +Several versions of the Lua interpreter are available: luajit, lua 5.1, 5.2, 5.3. +The attribute `lua` refers to the default interpreter, it is also possible to refer to specific versions, e.g. `lua5_2` refers to Lua 5.2. + +Lua libraries are in separate sets, with one set per interpreter version. + +The interpreters have several common attributes. One of these attributes is +`pkgs`, which is a package set of Lua libraries for this specific +interpreter. E.g., the `busted` package corresponding to the default interpreter +is `lua.pkgs.busted`, and the lua 5.2 version is `lua5_2.pkgs.busted`. +The main package set contains aliases to these package sets, e.g. +`luaPackages` refers to `lua5_1.pkgs` and `lua52Packages` to +`lua5_2.pkgs`. + +### Installing Lua and packages {#installing-lua-and-packages} + +#### Lua environment defined in separate `.nix` file {#lua-environment-defined-in-separate-.nix-file} + +Create a file, e.g. `build.nix`, with the following expression + +```nix +with import <nixpkgs> {}; + +lua5_2.withPackages (ps: with ps; [ busted luafilesystem ]) +``` + +and install it in your profile with + +```shell +nix-env -if build.nix +``` +Now you can use the Lua interpreter, as well as the extra packages (`busted`, +`luafilesystem`) that you added to the environment. + +#### Lua environment defined in `~/.config/nixpkgs/config.nix` {#lua-environment-defined-in-.confignixpkgsconfig.nix} + +If you prefer to, you could also add the environment as a package override to the Nixpkgs set, e.g. +using `config.nix`, + +```nix +{ # ... + + packageOverrides = pkgs: with pkgs; { + myLuaEnv = lua5_2.withPackages (ps: with ps; [ busted luafilesystem ]); + }; +} +``` + +and install it in your profile with + +```shell +nix-env -iA nixpkgs.myLuaEnv +``` +The environment is installed by referring to the attribute, and considering +the `nixpkgs` channel was used. + +#### Lua environment defined in `/etc/nixos/configuration.nix` {#lua-environment-defined-in-etcnixosconfiguration.nix} + +For the sake of completeness, here's another example how to install the environment system-wide. + +```nix +{ # ... + + environment.systemPackages = with pkgs; [ + (lua.withPackages(ps: with ps; [ busted luafilesystem ])) + ]; +} +``` + +### How to override a Lua package using overlays? {#how-to-override-a-lua-package-using-overlays} + +Use the following overlay template: + +```nix +final: prev: +{ + + lua = prev.lua.override { + packageOverrides = luaself: luaprev: { + + luarocks-nix = luaprev.luarocks-nix.overrideAttrs(oa: { + pname = "luarocks-nix"; + src = /home/my_luarocks/repository; + }); + }; + + luaPackages = lua.pkgs; +} +``` + +### Temporary Lua environment with `nix-shell` {#temporary-lua-environment-with-nix-shell} + + +There are two methods for loading a shell with Lua packages. The first and recommended method +is to create an environment with `lua.buildEnv` or `lua.withPackages` and load that. E.g. + +```sh +$ nix-shell -p 'lua.withPackages(ps: with ps; [ busted luafilesystem ])' +``` + +opens a shell from which you can launch the interpreter + +```sh +[nix-shell:~] lua +``` + +The other method, which is not recommended, does not create an environment and requires you to list the packages directly, + +```sh +$ nix-shell -p lua.pkgs.busted lua.pkgs.luafilesystem +``` +Again, it is possible to launch the interpreter from the shell. +The Lua interpreter has the attribute `pkgs` which contains all Lua libraries for that specific interpreter. + + +## Developing with Lua {#developing-with-lua} + +Now that you know how to get a working Lua environment with Nix, it is time +to go forward and start actually developing with Lua. There are two ways to +package lua software, either it is on luarocks and most of it can be taken care +of by the luarocks2nix converter or the packaging has to be done manually. +Let's present the luarocks way first and the manual one in a second time. + +### Packaging a library on luarocks {#packaging-a-library-on-luarocks} + +[Luarocks.org](https://luarocks.org/) is the main repository of lua packages. +The site proposes two types of packages, the rockspec and the src.rock +(equivalent of a [rockspec](https://github.com/luarocks/luarocks/wiki/Rockspec-format) but with the source). +These packages can have different build types such as `cmake`, `builtin` etc . + +Luarocks-based packages are generated in pkgs/development/lua-modules/generated-packages.nix from +the whitelist maintainers/scripts/luarocks-packages.csv and updated by running maintainers/scripts/update-luarocks-packages. + +[luarocks2nix](https://github.com/nix-community/luarocks) is a tool capable of generating nix derivations from both rockspec and src.rock (and favors the src.rock). +The automation only goes so far though and some packages need to be customized. +These customizations go in `pkgs/development/lua-modules/overrides.nix`. +For instance if the rockspec defines `external_dependencies`, these need to be manually added to the overrides.nix. + +You can try converting luarocks packages to nix packages with the command `nix-shell -p luarocks-nix` and then `luarocks nix PKG_NAME`. + +#### Packaging a library manually {#packaging-a-library-manually} + +You can develop your package as you usually would, just don't forget to wrap it +within a `toLuaModule` call, for instance + +```nix +mynewlib = toLuaModule ( stdenv.mkDerivation { ... }); +``` + +There is also the `buildLuaPackage` function that can be used when lua modules +are not packaged for luarocks. You can see a few examples at `pkgs/top-level/lua-packages.nix`. + +## Lua Reference {#lua-reference} + +### Lua interpreters {#lua-interpreters} + +Versions 5.1, 5.2, 5.3 and 5.4 of the lua interpreter are available as +respectively `lua5_1`, `lua5_2`, `lua5_3` and `lua5_4`. Luajit is available too. +The Nix expressions for the interpreters can be found in `pkgs/development/interpreters/lua-5`. + +#### Attributes on lua interpreters packages {#attributes-on-lua-interpreters-packages} + +Each interpreter has the following attributes: + +- `interpreter`. Alias for `${pkgs.lua}/bin/lua`. +- `buildEnv`. Function to build lua interpreter environments with extra packages bundled together. See section *lua.buildEnv function* for usage and documentation. +- `withPackages`. Simpler interface to `buildEnv`. +- `pkgs`. Set of Lua packages for that specific interpreter. The package set can be modified by overriding the interpreter and passing `packageOverrides`. + +#### `buildLuarocksPackage` function {#buildluarockspackage-function} + +The `buildLuarocksPackage` function is implemented in `pkgs/development/interpreters/lua-5/build-lua-package.nix` +The following is an example: +```nix +luaposix = buildLuarocksPackage { + pname = "luaposix"; + version = "34.0.4-1"; + + src = fetchurl { + url = "https://raw.githubusercontent.com/rocks-moonscript-org/moonrocks-mirror/master/luaposix-34.0.4-1.src.rock"; + sha256 = "0yrm5cn2iyd0zjd4liyj27srphvy0gjrjx572swar6zqr4dwjqp2"; + }; + disabled = (luaOlder "5.1") || (luaAtLeast "5.4"); + propagatedBuildInputs = [ bit32 lua std_normalize ]; + + meta = with lib; { + homepage = "https://github.com/luaposix/luaposix/"; + description = "Lua bindings for POSIX"; + maintainers = with maintainers; [ vyp lblasc ]; + license.fullName = "MIT/X11"; + }; +}; +``` + +The `buildLuarocksPackage` delegates most tasks to luarocks: + +* it adds `luarocks` as an unpacker for `src.rock` files (zip files really). +* configurePhase` writes a temporary luarocks configuration file which location +is exported via the environment variable `LUAROCKS_CONFIG`. +* the `buildPhase` does nothing. +* `installPhase` calls `luarocks make --deps-mode=none --tree $out` to build and +install the package +* In the `postFixup` phase, the `wrapLuaPrograms` bash function is called to + wrap all programs in the `$out/bin/*` directory to include `$PATH` + environment variable and add dependent libraries to script's `LUA_PATH` and + `LUA_CPATH`. + +By default `meta.platforms` is set to the same value as the interpreter unless overridden otherwise. + +#### `buildLuaApplication` function {#buildluaapplication-function} + +The `buildLuaApplication` function is practically the same as `buildLuaPackage`. +The difference is that `buildLuaPackage` by default prefixes the names of the packages with the version of the interpreter. +Because with an application we're not interested in multiple version the prefix is dropped. + +#### lua.withPackages function {#lua.withpackages-function} + +The `lua.withPackages` takes a function as an argument that is passed the set of lua packages and returns the list of packages to be included in the environment. +Using the `withPackages` function, the previous example for the luafilesystem environment can be written like this: + +```nix +with import <nixpkgs> {}; + +lua.withPackages (ps: [ps.luafilesystem]) +``` + +`withPackages` passes the correct package set for the specific interpreter version as an argument to the function. In the above example, `ps` equals `luaPackages`. +But you can also easily switch to using `lua5_2`: + +```nix +with import <nixpkgs> {}; + +lua5_2.withPackages (ps: [ps.lua]) +``` + +Now, `ps` is set to `lua52Packages`, matching the version of the interpreter. + +### Possible Todos {#possible-todos} + +* export/use version specific variables such as `LUA_PATH_5_2`/`LUAROCKS_CONFIG_5_2` +* let luarocks check for dependencies via exporting the different rocktrees in temporary config + +### Lua Contributing guidelines {#lua-contributing-guidelines} + +Following rules should be respected: + +* Make sure libraries build for all Lua interpreters. +* Commit names of Lua libraries should reflect that they are Lua libraries, so write for example `luaPackages.luafilesystem: 1.11 -> 1.12`. diff --git a/doc/languages-frameworks/maven.section.md b/doc/languages-frameworks/maven.section.md new file mode 100644 index 00000000000..f53a6fa8ac2 --- /dev/null +++ b/doc/languages-frameworks/maven.section.md @@ -0,0 +1,351 @@ +# Maven {#maven} + +Maven is a well-known build tool for the Java ecosystem however it has some challenges when integrating into the Nix build system. + +The following provides a list of common patterns with how to package a Maven project (or any JVM language that can export to Maven) as a Nix package. + +For the purposes of this example let's consider a very basic Maven project with the following `pom.xml` with a single dependency on [emoji-java](https://github.com/vdurmont/emoji-java). + +```xml +<?xml version="1.0" encoding="UTF-8"?> +<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> + <modelVersion>4.0.0</modelVersion> + <groupId>io.github.fzakaria</groupId> + <artifactId>maven-demo</artifactId> + <version>1.0</version> + <packaging>jar</packaging> + <name>NixOS Maven Demo</name> + + <dependencies> + <dependency> + <groupId>com.vdurmont</groupId> + <artifactId>emoji-java</artifactId> + <version>5.1.1</version> + </dependency> + </dependencies> +</project> +``` + +Our main class file will be very simple: + +```java +import com.vdurmont.emoji.EmojiParser; + +public class Main { + public static void main(String[] args) { + String str = "NixOS :grinning: is super cool :smiley:!"; + String result = EmojiParser.parseToUnicode(str); + System.out.println(result); + } +} +``` + +You find this demo project at https://github.com/fzakaria/nixos-maven-example + +## Solving for dependencies {#solving-for-dependencies} + +### buildMaven with NixOS/mvn2nix-maven-plugin {#buildmaven-with-nixosmvn2nix-maven-plugin} + +> ⚠️ Although `buildMaven` is the "blessed" way within nixpkgs, as of 2020, it hasn't seen much activity in quite a while. + +`buildMaven` is an alternative method that tries to follow similar patterns of other programming languages by generating a lock file. It relies on the maven plugin [mvn2nix-maven-plugin](https://github.com/NixOS/mvn2nix-maven-plugin). + +First you generate a `project-info.json` file using the maven plugin. + +> This should be executed in the project's source repository or be told which `pom.xml` to execute with. + +```bash +# run this step within the project's source repository +❯ mvn org.nixos.mvn2nix:mvn2nix-maven-plugin:mvn2nix + +❯ cat project-info.json | jq | head +{ + "project": { + "artifactId": "maven-demo", + "groupId": "org.nixos", + "version": "1.0", + "classifier": "", + "extension": "jar", + "dependencies": [ + { + "artifactId": "maven-resources-plugin", +``` + +This file is then given to the `buildMaven` function, and it returns 2 attributes. + +**`repo`**: + A Maven repository that is a symlink farm of all the dependencies found in the `project-info.json` + + +**`build`**: + A simple derivation that runs through `mvn compile` & `mvn package` to build the JAR. You may use this as inspiration for more complicated derivations. + +Here is an [example](https://github.com/fzakaria/nixos-maven-example/blob/main/build-maven-repository.nix) of building the Maven repository + +```nix +{ pkgs ? import <nixpkgs> { } }: +with pkgs; +(buildMaven ./project-info.json).repo +``` + +The benefit over the _double invocation_ as we will see below, is that the _/nix/store_ entry is a _linkFarm_ of every package, so that changes to your dependency set doesn't involve downloading everything from scratch. + +```bash +❯ tree $(nix-build --no-out-link build-maven-repository.nix) | head +/nix/store/g87va52nkc8jzbmi1aqdcf2f109r4dvn-maven-repository +├── antlr +│ └── antlr +│ └── 2.7.2 +│ ├── antlr-2.7.2.jar -> /nix/store/d027c8f2cnmj5yrynpbq2s6wmc9cb559-antlr-2.7.2.jar +│ └── antlr-2.7.2.pom -> /nix/store/mv42fc5gizl8h5g5vpywz1nfiynmzgp2-antlr-2.7.2.pom +├── avalon-framework +│ └── avalon-framework +│ └── 4.1.3 +│ ├── avalon-framework-4.1.3.jar -> /nix/store/iv5fp3955w3nq28ff9xfz86wvxbiw6n9-avalon-framework-4.1.3.jar +``` + +### Double Invocation {#double-invocation} + +> ⚠️ This pattern is the simplest but may cause unnecessary rebuilds due to the output hash changing. + +The double invocation is a _simple_ way to get around the problem that `nix-build` may be sandboxed and have no Internet connectivity. + +It treats the entire Maven repository as a single source to be downloaded, relying on Maven's dependency resolution to satisfy the output hash. This is similar to fetchers like `fetchgit`, except it has to run a Maven build to determine what to download. + +The first step will be to build the Maven project as a fixed-output derivation in order to collect the Maven repository -- below is an [example](https://github.com/fzakaria/nixos-maven-example/blob/main/double-invocation-repository.nix). + +> Traditionally the Maven repository is at `~/.m2/repository`. We will override this to be the `$out` directory. + +```nix +{ lib, stdenv, maven }: +stdenv.mkDerivation { + name = "maven-repository"; + buildInputs = [ maven ]; + src = ./.; # or fetchFromGitHub, cleanSourceWith, etc + buildPhase = '' + mvn package -Dmaven.repo.local=$out + ''; + + # keep only *.{pom,jar,sha1,nbm} and delete all ephemeral files with lastModified timestamps inside + installPhase = '' + find $out -type f \ + -name \*.lastUpdated -or \ + -name resolver-status.properties -or \ + -name _remote.repositories \ + -delete + ''; + + # don't do any fixup + dontFixup = true; + outputHashAlgo = "sha256"; + outputHashMode = "recursive"; + # replace this with the correct SHA256 + outputHash = lib.fakeSha256; +} +``` + +The build will fail, and tell you the expected `outputHash` to place. When you've set the hash, the build will return with a `/nix/store` entry whose contents are the full Maven repository. + +> Some additional files are deleted that would cause the output hash to change potentially on subsequent runs. + +```bash +❯ tree $(nix-build --no-out-link double-invocation-repository.nix) | head +/nix/store/8kicxzp98j68xyi9gl6jda67hp3c54fq-maven-repository +├── backport-util-concurrent +│ └── backport-util-concurrent +│ └── 3.1 +│ ├── backport-util-concurrent-3.1.pom +│ └── backport-util-concurrent-3.1.pom.sha1 +├── classworlds +│ └── classworlds +│ ├── 1.1 +│ │ ├── classworlds-1.1.jar +``` + +If your package uses _SNAPSHOT_ dependencies or _version ranges_; there is a strong likelihood that over-time your output hash will change since the resolved dependencies may change. Hence this method is less recommended then using `buildMaven`. + +## Building a JAR {#building-a-jar} + +Regardless of which strategy is chosen above, the step to build the derivation is the same. + +```nix +{ stdenv, maven, callPackage }: +# pick a repository derivation, here we will use buildMaven +let repository = callPackage ./build-maven-repository.nix { }; +in stdenv.mkDerivation rec { + pname = "maven-demo"; + version = "1.0"; + + src = builtins.fetchTarball "https://github.com/fzakaria/nixos-maven-example/archive/main.tar.gz"; + buildInputs = [ maven ]; + + buildPhase = '' + echo "Using repository ${repository}" + mvn --offline -Dmaven.repo.local=${repository} package; + ''; + + installPhase = '' + install -Dm644 target/${pname}-${version}.jar $out/share/java + ''; +} +``` + +> We place the library in `$out/share/java` since JDK package has a _stdenv setup hook_ that adds any JARs in the `share/java` directories of the build inputs to the CLASSPATH environment. + +```bash +❯ tree $(nix-build --no-out-link build-jar.nix) +/nix/store/7jw3xdfagkc2vw8wrsdv68qpsnrxgvky-maven-demo-1.0 +└── share + └── java + └── maven-demo-1.0.jar + +2 directories, 1 file +``` + +## Runnable JAR {#runnable-jar} + +The previous example builds a `jar` file but that's not a file one can run. + +You need to use it with `java -jar $out/share/java/output.jar` and make sure to provide the required dependencies on the classpath. + +The following explains how to use `makeWrapper` in order to make the derivation produce an executable that will run the JAR file you created. + +We will use the same repository we built above (either _double invocation_ or _buildMaven_) to setup a CLASSPATH for our JAR. + +The following two methods are more suited to Nix then building an [UberJar](https://imagej.net/Uber-JAR) which may be the more traditional approach. + +### CLASSPATH {#classpath} + +> This is ideal if you are providing a derivation for _nixpkgs_ and don't want to patch the project's `pom.xml`. + +We will read the Maven repository and flatten it to a single list. This list will then be concatenated with the _CLASSPATH_ separator to create the full classpath. + +We make sure to provide this classpath to the `makeWrapper`. + +```nix +{ stdenv, maven, callPackage, makeWrapper, jre }: +let + repository = callPackage ./build-maven-repository.nix { }; +in stdenv.mkDerivation rec { + pname = "maven-demo"; + version = "1.0"; + + src = builtins.fetchTarball + "https://github.com/fzakaria/nixos-maven-example/archive/main.tar.gz"; + buildInputs = [ maven makeWrapper ]; + + buildPhase = '' + echo "Using repository ${repository}" + mvn --offline -Dmaven.repo.local=${repository} package; + ''; + + installPhase = '' + mkdir -p $out/bin + + classpath=$(find ${repository} -name "*.jar" -printf ':%h/%f'); + install -Dm644 target/${pname}-${version}.jar $out/share/java + # create a wrapper that will automatically set the classpath + # this should be the paths from the dependency derivation + makeWrapper ${jre}/bin/java $out/bin/${pname} \ + --add-flags "-classpath $out/share/java/${pname}-${version}.jar:''${classpath#:}" \ + --add-flags "Main" + ''; +} +``` + +### MANIFEST file via Maven Plugin {#manifest-file-via-maven-plugin} + +> This is ideal if you are the project owner and want to change your `pom.xml` to set the CLASSPATH within it. + +Augment the `pom.xml` to create a JAR with the following manifest: + +```xml +<build> + <plugins> + <plugin> + <artifactId>maven-jar-plugin</artifactId> + <configuration> + <archive> + <manifest> + <addClasspath>true</addClasspath> + <classpathPrefix>../../repository/</classpathPrefix> + <classpathLayoutType>repository</classpathLayoutType> + <mainClass>Main</mainClass> + </manifest> + <manifestEntries> + <Class-Path>.</Class-Path> + </manifestEntries> + </archive> + </configuration> + </plugin> + </plugins> +</build> +``` + +The above plugin instructs the JAR to look for the necessary dependencies in the `lib/` relative folder. The layout of the folder is also in the _maven repository_ style. + +```bash +❯ unzip -q -c $(nix-build --no-out-link runnable-jar.nix)/share/java/maven-demo-1.0.jar META-INF/MANIFEST.MF + +Manifest-Version: 1.0 +Archiver-Version: Plexus Archiver +Built-By: nixbld +Class-Path: . ../../repository/com/vdurmont/emoji-java/5.1.1/emoji-jav + a-5.1.1.jar ../../repository/org/json/json/20170516/json-20170516.jar +Created-By: Apache Maven 3.6.3 +Build-Jdk: 1.8.0_265 +Main-Class: Main +``` + +We will modify the derivation above to add a symlink to our repository so that it's accessible to our JAR during the `installPhase`. + +```nix +{ stdenv, maven, callPackage, makeWrapper, jre }: +# pick a repository derivation, here we will use buildMaven +let repository = callPackage ./build-maven-repository.nix { }; +in stdenv.mkDerivation rec { + pname = "maven-demo"; + version = "1.0"; + + src = builtins.fetchTarball + "https://github.com/fzakaria/nixos-maven-example/archive/main.tar.gz"; + buildInputs = [ maven makeWrapper ]; + + buildPhase = '' + echo "Using repository ${repository}" + mvn --offline -Dmaven.repo.local=${repository} package; + ''; + + installPhase = '' + mkdir -p $out/bin + + # create a symbolic link for the repository directory + ln -s ${repository} $out/repository + + install -Dm644 target/${pname}-${version}.jar $out/share/java + # create a wrapper that will automatically set the classpath + # this should be the paths from the dependency derivation + makeWrapper ${jre}/bin/java $out/bin/${pname} \ + --add-flags "-jar $out/share/java/${pname}-${version}.jar" + ''; +} +``` + +> Our script produces a dependency on `jre` rather than `jdk` to restrict the runtime closure necessary to run the application. + +This will give you an executable shell-script that launches your JAR with all the dependencies available. + +```bash +❯ tree $(nix-build --no-out-link runnable-jar.nix) +/nix/store/8d4c3ibw8ynsn01ibhyqmc1zhzz75s26-maven-demo-1.0 +├── bin +│ └── maven-demo +├── repository -> /nix/store/g87va52nkc8jzbmi1aqdcf2f109r4dvn-maven-repository +└── share + └── java + └── maven-demo-1.0.jar + +❯ $(nix-build --no-out-link --option tarball-ttl 1 runnable-jar.nix)/bin/maven-demo +NixOS 😀 is super cool 😃! +``` diff --git a/doc/languages-frameworks/nim.section.md b/doc/languages-frameworks/nim.section.md new file mode 100644 index 00000000000..16dce61d71c --- /dev/null +++ b/doc/languages-frameworks/nim.section.md @@ -0,0 +1,91 @@ +# Nim {#nim} + +## Overview {#nim-overview} + +The Nim compiler, a builder function, and some packaged libraries are available +in Nixpkgs. Until now each compiler release has been effectively backwards +compatible so only the latest version is available. + +## Nim program packages in Nixpkgs {#nim-program-packages-in-nixpkgs} + +Nim programs can be built using `nimPackages.buildNimPackage`. In the +case of packages not containing exported library code the attribute +`nimBinOnly` should be set to `true`. + +The following example shows a Nim program that depends only on Nim libraries: + +```nix +{ lib, nimPackages, fetchurl }: + +nimPackages.buildNimPackage rec { + pname = "hottext"; + version = "1.4"; + + nimBinOnly = true; + + src = fetchurl { + url = "https://git.sr.ht/~ehmry/hottext/archive/v${version}.tar.gz"; + sha256 = "sha256-hIUofi81zowSMbt1lUsxCnVzfJGN3FEiTtN8CEFpwzY="; + }; + + buildInputs = with nimPackages; [ + bumpy + chroma + flatty + nimsimd + pixie + sdl2 + typography + vmath + zippy + ]; +} + +``` + +## Nim library packages in Nixpkgs {#nim-library-packages-in-nixpkgs} + + +Nim libraries can also be built using `nimPackages.buildNimPackage`, but +often the product of a fetcher is sufficient to satisfy a dependency. +The `fetchgit`, `fetchFromGitHub`, and `fetchNimble` functions yield an +output that can be discovered during the `configurePhase` of `buildNimPackage`. + +Nim library packages are listed in +[pkgs/top-level/nim-packages.nix](https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/nim-packages.nix) and implemented at +[pkgs/development/nim-packages](https://github.com/NixOS/nixpkgs/tree/master/pkgs/development/nim-packages). + +The following example shows a Nim library that propagates a dependency on a +non-Nim package: +```nix +{ lib, buildNimPackage, fetchNimble, SDL2 }: + +buildNimPackage rec { + pname = "sdl2"; + version = "2.0.4"; + src = fetchNimble { + inherit pname version; + hash = "sha256-Vtcj8goI4zZPQs2TbFoBFlcR5UqDtOldaXSH/+/xULk="; + }; + propagatedBuildInputs = [ SDL2 ]; +} +``` + +## `buildNimPackage` parameters {#buildnimpackage-parameters} + +All parameters from `stdenv.mkDerivation` function are still supported. The +following are specific to `buildNimPackage`: + +* `nimBinOnly ? false`: If `true` then build only the programs listed in + the Nimble file in the packages sources. +* `nimbleFile`: Specify the Nimble file location of the package being built + rather than discover the file at build-time. +* `nimRelease ? true`: Build the package in *release* mode. +* `nimDefines ? []`: A list of Nim defines. Key-value tuples are not supported. +* `nimFlags ? []`: A list of command line arguments to pass to the Nim compiler. + Use this to specify defines with arguments in the form of `-d:${name}=${value}`. +* `nimDoc` ? false`: Build and install HTML documentation. + +* `buildInputs` ? []: The packages listed here will be searched for `*.nimble` + files which are used to populate the Nim library path. Otherwise the standard + behavior is in effect. diff --git a/doc/languages-frameworks/ocaml.section.md b/doc/languages-frameworks/ocaml.section.md new file mode 100644 index 00000000000..e4813d7dd2d --- /dev/null +++ b/doc/languages-frameworks/ocaml.section.md @@ -0,0 +1,127 @@ +# OCaml {#sec-language-ocaml} + +## User guide {#sec-language-ocaml-user-guide} + +OCaml libraries are available in attribute sets of the form `ocaml-ng.ocamlPackages_X_XX` where X is to be replaced with the desired compiler version. For example, ocamlgraph compiled with OCaml 4.12 can be found in `ocaml-ng.ocamlPackages_4_12.ocamlgraph`. The compiler itself is also located in this set, under the name `ocaml`. + +If you don't care about the exact compiler version, `ocamlPackages` is a top-level alias pointing to a recent version of OCaml. + +OCaml applications are usually available top-level, and not inside `ocamlPackages`. Notable exceptions are build tools that must be built with the same compiler version as the compiler you intend to use like `dune` or `ocaml-lsp`. + +To open a shell able to build a typical OCaml project, put the dependencies in `buildInputs` and add `ocamlPackages.ocaml` and `ocamlPackages.findlib` to `nativeBuildInputs` at least. +For example: +```nix +let + pkgs = import <nixpkgs> {}; + # choose the ocaml version you want to use + ocamlPackages = pkgs.ocaml-ng.ocamlPackages_4_12; +in +pkgs.mkShell { + # build tools + nativeBuildInputs = with ocamlPackages; [ ocaml findlib dune_2 ocaml-lsp ]; + # dependencies + buildInputs = with ocamlPackages; [ ocamlgraph ]; +} +``` + +## Packaging guide {#sec-language-ocaml-packaging} + +OCaml libraries should be installed in `$(out)/lib/ocaml/${ocaml.version}/site-lib/`. Such directories are automatically added to the `$OCAMLPATH` environment variable when building another package that depends on them or when opening a `nix-shell`. + +Given that most of the OCaml ecosystem is now built with dune, nixpkgs includes a convenience build support function called `buildDunePackage` that will build an OCaml package using dune, OCaml and findlib and any additional dependencies provided as `buildInputs` or `propagatedBuildInputs`. + +Here is a simple package example. + +- It defines an (optional) attribute `minimalOCamlVersion` (see note below) + that will be used to throw a descriptive evaluation error if building with + an older OCaml is attempted. + +- It uses the `fetchFromGitHub` fetcher to get its source. + +- `useDune2 = true` ensures that Dune version 2 is used for the + build (this is the default; set to `false` to use Dune version 1). + +- It sets the optional `doCheck` attribute such that tests will be run with + `dune runtest -p angstrom` after the build (`dune build -p angstrom`) is + complete, but only if the Ocaml version is at at least `"4.05"`. + +- It uses the package `ocaml-syntax-shims` as a build input, `alcotest` and + `ppx_let` as check inputs (because they are needed to run the tests), and + `bigstringaf` and `result` as propagated build inputs (thus they will also be + available to libraries depending on this library). + +- The library will be installed using the `angstrom.install` file that dune + generates. + +```nix +{ lib, + fetchFromGitHub, + buildDunePackage, + ocaml, + ocaml-syntax-shims, + alcotest, + result, + bigstringaf, + ppx_let }: + +buildDunePackage rec { + pname = "angstrom"; + version = "0.15.0"; + useDune2 = true; + + minimalOCamlVersion = "4.04"; + + src = fetchFromGitHub { + owner = "inhabitedtype"; + repo = pname; + rev = version; + sha256 = "1hmrkdcdlkwy7rxhngf3cv3sa61cznnd9p5lmqhx20664gx2ibrh"; + }; + + checkInputs = [ alcotest ppx_let ]; + buildInputs = [ ocaml-syntax-shims ]; + propagatedBuildInputs = [ bigstringaf result ]; + doCheck = lib.versionAtLeast ocaml.version "4.05"; + + meta = { + homepage = "https://github.com/inhabitedtype/angstrom"; + description = "OCaml parser combinators built for speed and memory efficiency"; + license = lib.licenses.bsd3; + maintainers = with lib.maintainers; [ sternenseemann ]; + }; +``` + +Here is a second example, this time using a source archive generated with `dune-release`. It is a good idea to use this archive when it is available as it will usually contain substituted variables such as a `%%VERSION%%` field. This library does not depend on any other OCaml library and no tests are run after building it. + +```nix +{ lib, fetchurl, buildDunePackage }: + +buildDunePackage rec { + pname = "wtf8"; + version = "1.0.2"; + + useDune2 = true; + + minimalOCamlVersion = "4.02"; + + src = fetchurl { + url = "https://github.com/flowtype/ocaml-${pname}/releases/download/v${version}/${pname}-v${version}.tbz"; + sha256 = "09ygcxxd5warkdzz17rgpidrd0pg14cy2svvnvy1hna080lzg7vp"; + }; + + meta = with lib; { + homepage = "https://github.com/flowtype/ocaml-wtf8"; + description = "WTF-8 is a superset of UTF-8 that allows unpaired surrogates."; + license = licenses.mit; + maintainers = [ maintainers.eqyiel ]; + }; +} +``` + +Note about `minimalOCamlVersion`. A deprecated version of this argument was +spelled `minimumOCamlVersion`; setting the old attribute wrongly modifies the +derivation hash and is therefore inappropriate. As a technical dept, currently +packaged libraries may still use the old spelling: maintainers are invited to +fix this when updating packages. Massive renaming is strongly discouraged as it +would be challenging to review, difficult to test, and will cause unnecessary +rebuild. diff --git a/doc/languages-frameworks/octave.section.md b/doc/languages-frameworks/octave.section.md new file mode 100644 index 00000000000..4ad2cb0d5fb --- /dev/null +++ b/doc/languages-frameworks/octave.section.md @@ -0,0 +1,92 @@ +# Octave {#sec-octave} + +## Introduction {#ssec-octave-introduction} + +Octave is a modular scientific programming language and environment. +A majority of the packages supported by Octave from their [website](https://octave.sourceforge.io/packages.php) are packaged in nixpkgs. + +## Structure {#ssec-octave-structure} + +All Octave add-on packages are available in two ways: +1. Under the top-level `Octave` attribute, `octave.pkgs`. +2. As a top-level attribute, `octavePackages`. + +## Packaging Octave Packages {#ssec-octave-packaging} + +Nixpkgs provides a function `buildOctavePackage`, a generic package builder function for any Octave package that complies with the Octave's current packaging format. + +All Octave packages are defined in [pkgs/top-level/octave-packages.nix](https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/octave-packages.nix) rather than `pkgs/all-packages.nix`. +Each package is defined in their own file in the [pkgs/development/octave-modules](https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/octave-modules) directory. +Octave packages are made available through `all-packages.nix` through both the attribute `octavePackages` and `octave.pkgs`. +You can test building an Octave package as follows: + +```ShellSession +$ nix-build -A octavePackages.symbolic +``` + +To install it into your user profile, run this command from the root of the repository: + +```ShellSession +$ nix-env -f. -iA octavePackages.symbolic +``` + +You can build Octave with packages by using the `withPackages` passed-through function. + +```ShellSession +$ nix-shell -p 'octave.withPackages (ps: with ps; [ symbolic ])' +``` + +This will also work in a `shell.nix` file. + +```nix +{ pkgs ? import <nixpkgs> { }}: + +pkgs.mkShell { + nativeBuildInputs = with pkgs; [ + (octave.withPackages (opkgs: with opkgs; [ symbolic ])) + ]; +} +``` + +### `buildOctavePackage` Steps {#sssec-buildOctavePackage-steps} + +The `buildOctavePackage` does several things to make sure things work properly. + +1. Sets the environment variable `OCTAVE_HISTFILE` to `/dev/null` during package compilation so that the commands run through the Octave interpreter directly are not logged. +2. Skips the configuration step, because the packages are stored as gzipped tarballs, which Octave itself handles directly. +3. Change the hierarchy of the tarball so that only a single directory is at the top-most level of the tarball. +4. Use Octave itself to run the `pkg build` command, which unzips the tarball, extracts the necessary files written in Octave, and compiles any code written in C++ or Fortran, and places the fully compiled artifact in `$out`. + +`buildOctavePackage` is built on top of `stdenv` in a standard way, allowing most things to be customized. + +### Handling Dependencies {#sssec-octave-handling-dependencies} + +In Octave packages, there are four sets of dependencies that can be specified: + +`nativeBuildInputs` +: Just like other packages, `nativeBuildInputs` is intended for architecture-dependent build-time-only dependencies. + +`buildInputs` +: Like other packages, `buildInputs` is intended for architecture-independent build-time-only dependencies. + +`propagatedBuildInputs` +: Similar to other packages, `propagatedBuildInputs` is intended for packages that are required for both building and running of the package. +See [Symbolic](https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/octave-modules/symbolic/default.nix) for how this works and why it is needed. + +`requiredOctavePackages` +: This is a special dependency that ensures the specified Octave packages are dependent on others, and are made available simultaneously when loading them in Octave. + +### Installing Octave Packages {#sssec-installing-octave-packages} + +By default, the `buildOctavePackage` function does _not_ install the requested package into Octave for use. +The function will only build the requested package. +This is due to Octave maintaining an text-based database about which packages are installed where. +To this end, when all the requested packages have been built, the Octave package and all its add-on packages are put together into an environment, similar to Python. + +1. First, all the Octave binaries are wrapped with the environment variable `OCTAVE_SITE_INITFILE` set to a file in `$out`, which is required for Octave to be able to find the non-standard package database location. +2. Because of the way `buildEnv` works, all tarballs that are present (which should be all Octave packages to install) should be removed. +3. The path down to the default install location of Octave packages is recreated so that Nix-operated Octave can install the packages. +4. Install the packages into the `$out` environment while writing package entries to the database file. +This database file is unique for each different (according to Nix) environment invocation. +5. Rewrite the Octave-wide startup file to read from the list of packages installed in that particular environment. +6. Wrap any programs that are required by the Octave packages so that they work with all the paths defined within the environment. diff --git a/doc/languages-frameworks/perl.section.md b/doc/languages-frameworks/perl.section.md new file mode 100644 index 00000000000..9bfd209fec5 --- /dev/null +++ b/doc/languages-frameworks/perl.section.md @@ -0,0 +1,159 @@ +# Perl {#sec-language-perl} + +## Running perl programs on the shell {#ssec-perl-running} + +When executing a Perl script, it is possible you get an error such as `./myscript.pl: bad interpreter: /usr/bin/perl: no such file or directory`. This happens when the script expects Perl to be installed at `/usr/bin/perl`, which is not the case when using Perl from nixpkgs. You can fix the script by changing the first line to: + +```perl +#!/usr/bin/env perl +``` + +to take the Perl installation from the `PATH` environment variable, or invoke Perl directly with: + +```ShellSession +$ perl ./myscript.pl +``` + +When the script is using a Perl library that is not installed globally, you might get an error such as `Can't locate DB_File.pm in @INC (you may need to install the DB_File module)`. In that case, you can use `nix-shell` to start an ad-hoc shell with that library installed, for instance: + +```ShellSession +$ nix-shell -p perl perlPackages.DBFile --run ./myscript.pl +``` + +If you are always using the script in places where `nix-shell` is available, you can embed the `nix-shell` invocation in the shebang like this: + +```perl +#!/usr/bin/env nix-shell +#! nix-shell -i perl -p perl perlPackages.DBFile +``` + +## Packaging Perl programs {#ssec-perl-packaging} + +Nixpkgs provides a function `buildPerlPackage`, a generic package builder function for any Perl package that has a standard `Makefile.PL`. It’s implemented in [pkgs/development/perl-modules/generic](https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/perl-modules/generic). + +Perl packages from CPAN are defined in [pkgs/top-level/perl-packages.nix](https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix) rather than `pkgs/all-packages.nix`. Most Perl packages are so straight-forward to build that they are defined here directly, rather than having a separate function for each package called from `perl-packages.nix`. However, more complicated packages should be put in a separate file, typically in `pkgs/development/perl-modules`. Here is an example of the former: + +```nix +ClassC3 = buildPerlPackage rec { + name = "Class-C3-0.21"; + src = fetchurl { + url = "mirror://cpan/authors/id/F/FL/FLORA/${name}.tar.gz"; + sha256 = "1bl8z095y4js66pwxnm7s853pi9czala4sqc743fdlnk27kq94gz"; + }; +}; +``` + +Note the use of `mirror://cpan/`, and the `${name}` in the URL definition to ensure that the name attribute is consistent with the source that we’re actually downloading. Perl packages are made available in `all-packages.nix` through the variable `perlPackages`. For instance, if you have a package that needs `ClassC3`, you would typically write + +```nix +foo = import ../path/to/foo.nix { + inherit stdenv fetchurl ...; + inherit (perlPackages) ClassC3; +}; +``` + +in `all-packages.nix`. You can test building a Perl package as follows: + +```ShellSession +$ nix-build -A perlPackages.ClassC3 +``` + +To install it with `nix-env` instead: `nix-env -f. -iA perlPackages.ClassC3`. + +So what does `buildPerlPackage` do? It does the following: + +1. In the configure phase, it calls `perl Makefile.PL` to generate a Makefile. You can set the variable `makeMakerFlags` to pass flags to `Makefile.PL` +2. It adds the contents of the `PERL5LIB` environment variable to `#! .../bin/perl` line of Perl scripts as `-Idir` flags. This ensures that a script can find its dependencies. (This can cause this shebang line to become too long for Darwin to handle; see the note below.) +3. In the fixup phase, it writes the propagated build inputs (`propagatedBuildInputs`) to the file `$out/nix-support/propagated-user-env-packages`. `nix-env` recursively installs all packages listed in this file when you install a package that has it. This ensures that a Perl package can find its dependencies. + +`buildPerlPackage` is built on top of `stdenv`, so everything can be customised in the usual way. For instance, the `BerkeleyDB` module has a `preConfigure` hook to generate a configuration file used by `Makefile.PL`: + +```nix +{ buildPerlPackage, fetchurl, db }: + +buildPerlPackage rec { + name = "BerkeleyDB-0.36"; + + src = fetchurl { + url = "mirror://cpan/authors/id/P/PM/PMQS/${name}.tar.gz"; + sha256 = "07xf50riarb60l1h6m2dqmql8q5dij619712fsgw7ach04d8g3z1"; + }; + + preConfigure = '' + echo "LIB = ${db.out}/lib" > config.in + echo "INCLUDE = ${db.dev}/include" >> config.in + ''; +} +``` + +Dependencies on other Perl packages can be specified in the `buildInputs` and `propagatedBuildInputs` attributes. If something is exclusively a build-time dependency, use `buildInputs`; if it’s (also) a runtime dependency, use `propagatedBuildInputs`. For instance, this builds a Perl module that has runtime dependencies on a bunch of other modules: + +```nix +ClassC3Componentised = buildPerlPackage rec { + name = "Class-C3-Componentised-1.0004"; + src = fetchurl { + url = "mirror://cpan/authors/id/A/AS/ASH/${name}.tar.gz"; + sha256 = "0xql73jkcdbq4q9m0b0rnca6nrlvf5hyzy8is0crdk65bynvs8q1"; + }; + propagatedBuildInputs = [ + ClassC3 ClassInspector TestException MROCompat + ]; +}; +``` + +On Darwin, if a script has too many `-Idir` flags in its first line (its “shebang line”), it will not run. This can be worked around by calling the `shortenPerlShebang` function from the `postInstall` phase: + +```nix +{ lib, stdenv, buildPerlPackage, fetchurl, shortenPerlShebang }: + +ImageExifTool = buildPerlPackage { + pname = "Image-ExifTool"; + version = "11.50"; + + src = fetchurl { + url = "https://www.sno.phy.queensu.ca/~phil/exiftool/Image-ExifTool-11.50.tar.gz"; + sha256 = "0d8v48y94z8maxkmw1rv7v9m0jg2dc8xbp581njb6yhr7abwqdv3"; + }; + + buildInputs = lib.optional stdenv.isDarwin shortenPerlShebang; + postInstall = lib.optionalString stdenv.isDarwin '' + shortenPerlShebang $out/bin/exiftool + ''; +}; +``` + +This will remove the `-I` flags from the shebang line, rewrite them in the `use lib` form, and put them on the next line instead. This function can be given any number of Perl scripts as arguments; it will modify them in-place. + +### Generation from CPAN {#ssec-generation-from-CPAN} + +Nix expressions for Perl packages can be generated (almost) automatically from CPAN. This is done by the program `nix-generate-from-cpan`, which can be installed as follows: + +```ShellSession +$ nix-env -f "<nixpkgs>" -iA nix-generate-from-cpan +``` + +Substitute `<nixpkgs>` by the path of a nixpkgs clone to use the latest version. + +This program takes a Perl module name, looks it up on CPAN, fetches and unpacks the corresponding package, and prints a Nix expression on standard output. For example: + +```ShellSession +$ nix-generate-from-cpan XML::Simple + XMLSimple = buildPerlPackage rec { + name = "XML-Simple-2.22"; + src = fetchurl { + url = "mirror://cpan/authors/id/G/GR/GRANTM/${name}.tar.gz"; + sha256 = "b9450ef22ea9644ae5d6ada086dc4300fa105be050a2030ebd4efd28c198eb49"; + }; + propagatedBuildInputs = [ XMLNamespaceSupport XMLSAX XMLSAXExpat ]; + meta = { + description = "An API for simple XML files"; + license = with lib.licenses; [ artistic1 gpl1Plus ]; + }; + }; +``` + +The output can be pasted into `pkgs/top-level/perl-packages.nix` or wherever else you need it. + +### Cross-compiling modules {#ssec-perl-cross-compilation} + +Nixpkgs has experimental support for cross-compiling Perl modules. In many cases, it will just work out of the box, even for modules with native extensions. Sometimes, however, the Makefile.PL for a module may (indirectly) import a native module. In that case, you will need to make a stub for that module that will satisfy the Makefile.PL and install it into `lib/perl5/site_perl/cross_perl/${perl.version}`. See the `postInstall` for `DBI` for an example. diff --git a/doc/languages-frameworks/php.section.md b/doc/languages-frameworks/php.section.md new file mode 100644 index 00000000000..5977363323f --- /dev/null +++ b/doc/languages-frameworks/php.section.md @@ -0,0 +1,155 @@ +# PHP {#sec-php} + +## User Guide {#ssec-php-user-guide} + +### Overview {#ssec-php-user-guide-overview} + +Several versions of PHP are available on Nix, each of which having a +wide variety of extensions and libraries available. + +The different versions of PHP that nixpkgs provides are located under +attributes named based on major and minor version number; e.g., +`php74` is PHP 7.4. + +Only versions of PHP that are supported by upstream for the entirety +of a given NixOS release will be included in that release of +NixOS. See [PHP Supported +Versions](https://www.php.net/supported-versions.php). + +The attribute `php` refers to the version of PHP considered most +stable and thoroughly tested in nixpkgs for any given release of +NixOS - not necessarily the latest major release from upstream. + +All available PHP attributes are wrappers around their respective +binary PHP package and provide commonly used extensions this way. The +real PHP 7.4 package, i.e. the unwrapped one, is available as +`php74.unwrapped`; see the next section for more details. + +Interactive tools built on PHP are put in `php.packages`; composer is +for example available at `php.packages.composer`. + +Most extensions that come with PHP, as well as some popular +third-party ones, are available in `php.extensions`; for example, the +opcache extension shipped with PHP is available at +`php.extensions.opcache` and the third-party ImageMagick extension at +`php.extensions.imagick`. + +### Installing PHP with extensions {#ssec-php-user-guide-installing-with-extensions} + +A PHP package with specific extensions enabled can be built using +`php.withExtensions`. This is a function which accepts an anonymous +function as its only argument; the function should accept two named +parameters: `enabled` - a list of currently enabled extensions and +`all` - the set of all extensions, and return a list of wanted +extensions. For example, a PHP package with all default extensions and +ImageMagick enabled: + +```nix +php.withExtensions ({ enabled, all }: + enabled ++ [ all.imagick ]) +``` + +To exclude some, but not all, of the default extensions, you can +filter the `enabled` list like this: + +```nix +php.withExtensions ({ enabled, all }: + (lib.filter (e: e != php.extensions.opcache) enabled) + ++ [ all.imagick ]) +``` + +To build your list of extensions from the ground up, you can simply +ignore `enabled`: + +```nix +php.withExtensions ({ all, ... }: with all; [ imagick opcache ]) +``` + +`php.withExtensions` provides extensions by wrapping a minimal php +base package, providing a `php.ini` file listing all extensions to be +loaded. You can access this package through the `php.unwrapped` +attribute; useful if you, for example, need access to the `dev` +output. The generated `php.ini` file can be accessed through the +`php.phpIni` attribute. + +If you want a PHP build with extra configuration in the `php.ini` +file, you can use `php.buildEnv`. This function takes two named and +optional parameters: `extensions` and `extraConfig`. `extensions` +takes an extension specification equivalent to that of +`php.withExtensions`, `extraConfig` a string of additional `php.ini` +configuration parameters. For example, a PHP package with the opcache +and ImageMagick extensions enabled, and `memory_limit` set to `256M`: + +```nix +php.buildEnv { + extensions = { all, ... }: with all; [ imagick opcache ]; + extraConfig = "memory_limit=256M"; +} +``` + +#### Example setup for `phpfpm` {#ssec-php-user-guide-installing-with-extensions-phpfpm} + +You can use the previous examples in a `phpfpm` pool called `foo` as +follows: + +```nix +let + myPhp = php.withExtensions ({ all, ... }: with all; [ imagick opcache ]); +in { + services.phpfpm.pools."foo".phpPackage = myPhp; +}; +``` + +```nix +let + myPhp = php.buildEnv { + extensions = { all, ... }: with all; [ imagick opcache ]; + extraConfig = "memory_limit=256M"; + }; +in { + services.phpfpm.pools."foo".phpPackage = myPhp; +}; +``` + +#### Example usage with `nix-shell` {#ssec-php-user-guide-installing-with-extensions-nix-shell} + +This brings up a temporary environment that contains a PHP interpreter +with the extensions `imagick` and `opcache` enabled: + +```sh +nix-shell -p 'php.withExtensions ({ all, ... }: with all; [ imagick opcache ])' +``` + +### Installing PHP packages with extensions {#ssec-php-user-guide-installing-packages-with-extensions} + +All interactive tools use the PHP package you get them from, so all +packages at `php.packages.*` use the `php` package with its default +extensions. Sometimes this default set of extensions isn't enough and +you may want to extend it. A common case of this is the `composer` +package: a project may depend on certain extensions and `composer` +won't work with that project unless those extensions are loaded. + +Example of building `composer` with additional extensions: +```nix +(php.withExtensions ({ all, enabled }: + enabled ++ (with all; [ imagick redis ])) +).packages.composer +``` + +### Overriding PHP packages {#ssec-php-user-guide-overriding-packages} + +`php-packages.nix` form a scope, allowing us to override the packages defined within. For example, to apply a patch to a `mysqlnd` extension, you can simply pass an overlay-style function to `php`’s `packageOverrides` argument: + +```nix +php.override { + packageOverrides = final: prev: { + extensions = prev.extensions // { + mysqlnd = prev.extensions.mysqlnd.overrideAttrs (attrs: { + patches = attrs.patches or [] ++ [ + … + ]; + }); + }; + }; +} +``` diff --git a/doc/languages-frameworks/python.section.md b/doc/languages-frameworks/python.section.md new file mode 100644 index 00000000000..693ea016e0a --- /dev/null +++ b/doc/languages-frameworks/python.section.md @@ -0,0 +1,1682 @@ +# Python {#python} + +## User Guide {#user-guide} + +### Using Python {#using-python} + +#### Overview {#overview} + +Several versions of the Python interpreter are available on Nix, as well as a +high amount of packages. The attribute `python3` refers to the default +interpreter, which is currently CPython 3.9. The attribute `python` refers to +CPython 2.7 for backwards-compatibility. It is also possible to refer to +specific versions, e.g. `python38` refers to CPython 3.8, and `pypy` refers to +the default PyPy interpreter. + +Python is used a lot, and in different ways. This affects also how it is +packaged. In the case of Python on Nix, an important distinction is made between +whether the package is considered primarily an application, or whether it should +be used as a library, i.e., of primary interest are the modules in +`site-packages` that should be importable. + +In the Nixpkgs tree Python applications can be found throughout, depending on +what they do, and are called from the main package set. Python libraries, +however, are in separate sets, with one set per interpreter version. + +The interpreters have several common attributes. One of these attributes is +`pkgs`, which is a package set of Python libraries for this specific +interpreter. E.g., the `toolz` package corresponding to the default interpreter +is `python.pkgs.toolz`, and the CPython 3.8 version is `python38.pkgs.toolz`. +The main package set contains aliases to these package sets, e.g. +`pythonPackages` refers to `python.pkgs` and `python38Packages` to +`python38.pkgs`. + +#### Installing Python and packages {#installing-python-and-packages} + +The Nix and NixOS manuals explain how packages are generally installed. In the +case of Python and Nix, it is important to make a distinction between whether the +package is considered an application or a library. + +Applications on Nix are typically installed into your user profile imperatively +using `nix-env -i`, and on NixOS declaratively by adding the package name to +`environment.systemPackages` in `/etc/nixos/configuration.nix`. Dependencies +such as libraries are automatically installed and should not be installed +explicitly. + +The same goes for Python applications. Python applications can be installed in +your profile, and will be wrapped to find their exact library dependencies, +without impacting other applications or polluting your user environment. + +But Python libraries you would like to use for development cannot be installed, +at least not individually, because they won't be able to find each other +resulting in import errors. Instead, it is possible to create an environment +with `python.buildEnv` or `python.withPackages` where the interpreter and other +executables are wrapped to be able to find each other and all of the modules. + +In the following examples we will start by creating a simple, ad-hoc environment +with a nix-shell that has `numpy` and `toolz` in Python 3.8; then we will create +a re-usable environment in a single-file Python script; then we will create a +full Python environment for development with this same environment. + +Philosphically, this should be familiar to users who are used to a `venv` style +of development: individual projects create their own Python environments without +impacting the global environment or each other. + +#### Ad-hoc temporary Python environment with `nix-shell` {#ad-hoc-temporary-python-environment-with-nix-shell} + +The simplest way to start playing with the way nix wraps and sets up Python +environments is with `nix-shell` at the cmdline. These environments create a +temporary shell session with a Python and a *precise* list of packages (plus +their runtime dependencies), with no other Python packages in the Python +interpreter's scope. + +To create a Python 3.8 session with `numpy` and `toolz` available, run: + +```sh +$ nix-shell -p 'python38.withPackages(ps: with ps; [ numpy toolz ])' +``` + +By default `nix-shell` will start a `bash` session with this interpreter in our +`PATH`, so if we then run: + +```Python console +[nix-shell:~/src/nixpkgs]$ python3 +Python 3.8.1 (default, Dec 18 2019, 19:06:26) +[GCC 9.2.0] on linux +Type "help", "copyright", "credits" or "license" for more information. +>>> import numpy; import toolz +``` + +Note that no other modules are in scope, even if they were imperatively +installed into our user environment as a dependency of a Python application: + +```Python console +>>> import requests +Traceback (most recent call last): + File "<stdin>", line 1, in <module> +ModuleNotFoundError: No module named 'requests' +``` + +We can add as many additional modules onto the `nix-shell` as we need, and we +will still get 1 wrapped Python interpreter. We can start the interpreter +directly like so: + +```sh +$ nix-shell -p 'python38.withPackages(ps: with ps; [ numpy toolz requests ])' --run python3 +these derivations will be built: + /nix/store/xbdsrqrsfa1yva5s7pzsra8k08gxlbz1-python3-3.8.1-env.drv +building '/nix/store/xbdsrqrsfa1yva5s7pzsra8k08gxlbz1-python3-3.8.1-env.drv'... +created 277 symlinks in user environment +Python 3.8.1 (default, Dec 18 2019, 19:06:26) +[GCC 9.2.0] on linux +Type "help", "copyright", "credits" or "license" for more information. +>>> import requests +>>> +``` + +Notice that this time it built a new Python environment, which now includes +`requests`. Building an environment just creates wrapper scripts that expose the +selected dependencies to the interpreter while re-using the actual modules. This +means if any other env has installed `requests` or `numpy` in a different +context, we don't need to recompile them -- we just recompile the wrapper script +that sets up an interpreter pointing to them. This matters much more for "big" +modules like `pytorch` or `tensorflow`. + +Module names usually match their names on [pypi.org](https://pypi.org/), but +you can use the [Nixpkgs search website](https://nixos.org/nixos/packages.html) +to find them as well (along with non-python packages). + +At this point we can create throwaway experimental Python environments with +arbitrary dependencies. This is a good way to get a feel for how the Python +interpreter and dependencies work in Nix and NixOS, but to do some actual +development, we'll want to make it a bit more persistent. + +##### Running Python scripts and using `nix-shell` as shebang {#running-python-scripts-and-using-nix-shell-as-shebang} + +Sometimes, we have a script whose header looks like this: + +```python +#!/usr/bin/env python3 +import numpy as np +a = np.array([1,2]) +b = np.array([3,4]) +print(f"The dot product of {a} and {b} is: {np.dot(a, b)}") +``` + +Executing this script requires a `python3` that has `numpy`. Using what we learned +in the previous section, we could startup a shell and just run it like so: + +```ShellSession +$ nix-shell -p 'python38.withPackages(ps: with ps; [ numpy ])' --run 'python3 foo.py' +The dot product of [1 2] and [3 4] is: 11 +``` + +But if we maintain the script ourselves, and if there are more dependencies, it +may be nice to encode those dependencies in source to make the script re-usable +without that bit of knowledge. That can be done by using `nix-shell` as a +[shebang](https://en.wikipedia.org/wiki/Shebang_(Unix)), like so: + +```python +#!/usr/bin/env nix-shell +#!nix-shell -i python3 -p "python3.withPackages(ps: [ ps.numpy ])" +import numpy as np +a = np.array([1,2]) +b = np.array([3,4]) +print(f"The dot product of {a} and {b} is: {np.dot(a, b)}") +``` + +Then we simply execute it, without requiring any environment setup at all! + +```sh +$ ./foo.py +The dot product of [1 2] and [3 4] is: 11 +``` + +If the dependencies are not available on the host where `foo.py` is executed, it +will build or download them from a Nix binary cache prior to starting up, prior +that it is executed on a machine with a multi-user nix installation. + +This provides a way to ship a self bootstrapping Python script, akin to a +statically linked binary, where it can be run on any machine (provided nix is +installed) without having to assume that `numpy` is installed globally on the +system. + +By default it is pulling the import checkout of Nixpkgs itself from our nix +channel, which is nice as it cache aligns with our other package builds, but we +can make it fully reproducible by pinning the `nixpkgs` import: + +```python +#!/usr/bin/env nix-shell +#!nix-shell -i python3 -p "python3.withPackages(ps: [ ps.numpy ])" +#!nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/d373d80b1207d52621961b16aa4a3438e4f98167.tar.gz +import numpy as np +a = np.array([1,2]) +b = np.array([3,4]) +print(f"The dot product of {a} and {b} is: {np.dot(a, b)}") +``` + +This will execute with the exact same versions of Python 3.8, numpy, and system +dependencies a year from now as it does today, because it will always use +exactly git commit `d373d80b1207d52621961b16aa4a3438e4f98167` of Nixpkgs for all +of the package versions. + +This is also a great way to ensure the script executes identically on different +servers. + +##### Load environment from `.nix` expression {#load-environment-from-.nix-expression} + +We've now seen how to create an ad-hoc temporary shell session, and how to +create a single script with Python dependencies, but in the course of normal +development we're usually working in an entire package repository. + +As explained in the Nix manual, `nix-shell` can also load an expression from a +`.nix` file. Say we want to have Python 3.8, `numpy` and `toolz`, like before, +in an environment. We can add a `shell.nix` file describing our dependencies: + +```nix +with import <nixpkgs> {}; +(python38.withPackages (ps: [ps.numpy ps.toolz])).env +``` + +And then at the command line, just typing `nix-shell` produces the same +environment as before. In a normal project, we'll likely have many more +dependencies; this can provide a way for developers to share the environments +with each other and with CI builders. + +What's happening here? + +1. We begin with importing the Nix Packages collections. `import <nixpkgs>` + imports the `<nixpkgs>` function, `{}` calls it and the `with` statement + brings all attributes of `nixpkgs` in the local scope. These attributes form + the main package set. +2. Then we create a Python 3.8 environment with the `withPackages` function, as before. +3. The `withPackages` function expects us to provide a function as an argument + that takes the set of all Python packages and returns a list of packages to + include in the environment. Here, we select the packages `numpy` and `toolz` + from the package set. + +To combine this with `mkShell` you can: + +```nix +with import <nixpkgs> {}; +let + pythonEnv = python38.withPackages (ps: [ + ps.numpy + ps.toolz + ]); +in mkShell { + packages = [ + pythonEnv + + black + mypy + + libffi + openssl + ]; +} +``` + +This will create a unified environment that has not just our Python interpreter +and its Python dependencies, but also tools like `black` or `mypy` and libraries +like `libffi` the `openssl` in scope. This is generic and can span any number of +tools or languages across the Nixpkgs ecosystem. + +##### Installing environments globally on the system {#installing-environments-globally-on-the-system} + +Up to now, we've been creating environments scoped to an ad-hoc shell session, +or a single script, or a single project. This is generally advisable, as it +avoids pollution across contexts. + +However, sometimes we know we will often want a Python with some basic packages, +and want this available without having to enter into a shell or build context. +This can be useful to have things like vim/emacs editors and plugins or shell +tools "just work" without having to set them up, or when running other software +that expects packages to be installed globally. + +To create your own custom environment, create a file in `~/.config/nixpkgs/overlays/` +that looks like this: + +```nix +# ~/.config/nixpkgs/overlays/myEnv.nix +self: super: { + myEnv = super.buildEnv { + name = "myEnv"; + paths = [ + # A Python 3 interpreter with some packages + (self.python3.withPackages ( + ps: with ps; [ + pyflakes + pytest + python-language-server + ] + )) + + # Some other packages we'd like as part of this env + self.mypy + self.black + self.ripgrep + self.tmux + ]; + }; +} +``` + +You can then build and install this to your profile with: + +```sh +nix-env -iA myEnv +``` + +One limitation of this is that you can only have 1 Python env installed +globally, since they conflict on the `python` to load out of your `PATH`. + +If you get a conflict or prefer to keep the setup clean, you can have `nix-env` +atomically *uninstall* all other imperatively installed packages and replace +your profile with just `myEnv` by using the `--replace` flag. + +##### Environment defined in `/etc/nixos/configuration.nix` {#environment-defined-in-etcnixosconfiguration.nix} + +For the sake of completeness, here's how to install the environment system-wide +on NixOS. + +```nix +{ # ... + + environment.systemPackages = with pkgs; [ + (python38.withPackages(ps: with ps; [ numpy toolz ])) + ]; +} +``` + +### Developing with Python {#developing-with-python} + +Above, we were mostly just focused on use cases and what to do to get started +creating working Python environments in nix. + +Now that you know the basics to be up and running, it is time to take a step +back and take a deeper look at how Python packages are packaged on Nix. Then, +we will look at how you can use development mode with your code. + +#### Python library packages in Nixpkgs {#python-library-packages-in-nixpkgs} + +With Nix all packages are built by functions. The main function in Nix for +building Python libraries is `buildPythonPackage`. Let's see how we can build the +`toolz` package. + +```nix +{ lib, buildPythonPackage, fetchPypi }: + +buildPythonPackage rec { + pname = "toolz"; + version = "0.10.0"; + + src = fetchPypi { + inherit pname version; + sha256 = "08fdd5ef7c96480ad11c12d472de21acd32359996f69a5259299b540feba4560"; + }; + + doCheck = false; + + meta = with lib; { + homepage = "https://github.com/pytoolz/toolz"; + description = "List processing tools and functional utilities"; + license = licenses.bsd3; + maintainers = with maintainers; [ fridh ]; + }; +} +``` + +What happens here? The function `buildPythonPackage` is called and as argument +it accepts a set. In this case the set is a recursive set, `rec`. One of the +arguments is the name of the package, which consists of a basename (generally +following the name on PyPi) and a version. Another argument, `src` specifies the +source, which in this case is fetched from PyPI using the helper function +`fetchPypi`. The argument `doCheck` is used to set whether tests should be run +when building the package. Furthermore, we specify some (optional) meta +information. The output of the function is a derivation. + +An expression for `toolz` can be found in the Nixpkgs repository. As explained +in the introduction of this Python section, a derivation of `toolz` is available +for each interpreter version, e.g. `python38.pkgs.toolz` refers to the `toolz` +derivation corresponding to the CPython 3.8 interpreter. + +The above example works when you're directly working on +`pkgs/top-level/python-packages.nix` in the Nixpkgs repository. Often though, +you will want to test a Nix expression outside of the Nixpkgs tree. + +The following expression creates a derivation for the `toolz` package, +and adds it along with a `numpy` package to a Python environment. + +```nix +with import <nixpkgs> {}; + +( let + my_toolz = python38.pkgs.buildPythonPackage rec { + pname = "toolz"; + version = "0.10.0"; + + src = python38.pkgs.fetchPypi { + inherit pname version; + sha256 = "08fdd5ef7c96480ad11c12d472de21acd32359996f69a5259299b540feba4560"; + }; + + doCheck = false; + + meta = { + homepage = "https://github.com/pytoolz/toolz/"; + description = "List processing tools and functional utilities"; + }; + }; + + in python38.withPackages (ps: [ps.numpy my_toolz]) +).env +``` + +Executing `nix-shell` will result in an environment in which you can use +Python 3.8 and the `toolz` package. As you can see we had to explicitly mention +for which Python version we want to build a package. + +So, what did we do here? Well, we took the Nix expression that we used earlier +to build a Python environment, and said that we wanted to include our own +version of `toolz`, named `my_toolz`. To introduce our own package in the scope +of `withPackages` we used a `let` expression. You can see that we used +`ps.numpy` to select numpy from the nixpkgs package set (`ps`). We did not take +`toolz` from the Nixpkgs package set this time, but instead took our own version +that we introduced with the `let` expression. + +#### Handling dependencies {#handling-dependencies} + +Our example, `toolz`, does not have any dependencies on other Python packages or +system libraries. According to the manual, `buildPythonPackage` uses the +arguments `buildInputs` and `propagatedBuildInputs` to specify dependencies. If +something is exclusively a build-time dependency, then the dependency should be +included in `buildInputs`, but if it is (also) a runtime dependency, then it +should be added to `propagatedBuildInputs`. Test dependencies are considered +build-time dependencies and passed to `checkInputs`. + +The following example shows which arguments are given to `buildPythonPackage` in +order to build [`datashape`](https://github.com/blaze/datashape). + +```nix +{ lib, buildPythonPackage, fetchPypi, numpy, multipledispatch, python-dateutil, pytest }: + +buildPythonPackage rec { + pname = "datashape"; + version = "0.4.7"; + + src = fetchPypi { + inherit pname version; + sha256 = "14b2ef766d4c9652ab813182e866f493475e65e558bed0822e38bf07bba1a278"; + }; + + checkInputs = [ pytest ]; + propagatedBuildInputs = [ numpy multipledispatch python-dateutil ]; + + meta = with lib; { + homepage = "https://github.com/ContinuumIO/datashape"; + description = "A data description language"; + license = licenses.bsd2; + maintainers = with maintainers; [ fridh ]; + }; +} +``` + +We can see several runtime dependencies, `numpy`, `multipledispatch`, and +`python-dateutil`. Furthermore, we have one `checkInputs`, i.e. `pytest`. `pytest` is a +test runner and is only used during the `checkPhase` and is therefore not added +to `propagatedBuildInputs`. + +In the previous case we had only dependencies on other Python packages to consider. +Occasionally you have also system libraries to consider. E.g., `lxml` provides +Python bindings to `libxml2` and `libxslt`. These libraries are only required +when building the bindings and are therefore added as `buildInputs`. + +```nix +{ lib, pkgs, buildPythonPackage, fetchPypi }: + +buildPythonPackage rec { + pname = "lxml"; + version = "3.4.4"; + + src = fetchPypi { + inherit pname version; + sha256 = "16a0fa97hym9ysdk3rmqz32xdjqmy4w34ld3rm3jf5viqjx65lxk"; + }; + + buildInputs = [ pkgs.libxml2 pkgs.libxslt ]; + + meta = with lib; { + description = "Pythonic binding for the libxml2 and libxslt libraries"; + homepage = "https://lxml.de"; + license = licenses.bsd3; + maintainers = with maintainers; [ sjourdois ]; + }; +} +``` + +In this example `lxml` and Nix are able to work out exactly where the relevant +files of the dependencies are. This is not always the case. + +The example below shows bindings to The Fastest Fourier Transform in the West, +commonly known as FFTW. On Nix we have separate packages of FFTW for the +different types of floats (`"single"`, `"double"`, `"long-double"`). The +bindings need all three types, and therefore we add all three as `buildInputs`. +The bindings don't expect to find each of them in a different folder, and +therefore we have to set `LDFLAGS` and `CFLAGS`. + +```nix +{ lib, pkgs, buildPythonPackage, fetchPypi, numpy, scipy }: + +buildPythonPackage rec { + pname = "pyFFTW"; + version = "0.9.2"; + + src = fetchPypi { + inherit pname version; + sha256 = "f6bbb6afa93085409ab24885a1a3cdb8909f095a142f4d49e346f2bd1b789074"; + }; + + buildInputs = [ pkgs.fftw pkgs.fftwFloat pkgs.fftwLongDouble]; + + propagatedBuildInputs = [ numpy scipy ]; + + # Tests cannot import pyfftw. pyfftw works fine though. + doCheck = false; + + preConfigure = '' + export LDFLAGS="-L${pkgs.fftw.dev}/lib -L${pkgs.fftwFloat.out}/lib -L${pkgs.fftwLongDouble.out}/lib" + export CFLAGS="-I${pkgs.fftw.dev}/include -I${pkgs.fftwFloat.dev}/include -I${pkgs.fftwLongDouble.dev}/include" + ''; + + meta = with lib; { + description = "A pythonic wrapper around FFTW, the FFT library, presenting a unified interface for all the supported transforms"; + homepage = "http://hgomersall.github.com/pyFFTW"; + license = with licenses; [ bsd2 bsd3 ]; + maintainers = with maintainers; [ fridh ]; + }; +} +``` + +Note also the line `doCheck = false;`, we explicitly disabled running the test-suite. + +#### Testing Python Packages {#testing-python-packages} + +It is highly encouraged to have testing as part of the package build. This +helps to avoid situations where the package was able to build and install, +but is not usable at runtime. Currently, all packages will use the `test` +command provided by the setup.py (i.e. `python setup.py test`). However, +this is currently deprecated https://github.com/pypa/setuptools/pull/1878 +and your package should provide its own checkPhase. + +*NOTE:* The `checkPhase` for python maps to the `installCheckPhase` on a +normal derivation. This is due to many python packages not behaving well +to the pre-installed version of the package. Version info, and natively +compiled extensions generally only exist in the install directory, and +thus can cause issues when a test suite asserts on that behavior. + +*NOTE:* Tests should only be disabled if they don't agree with nix +(e.g. external dependencies, network access, flakey tests), however, +as many tests should be enabled as possible. Failing tests can still be +a good indication that the package is not in a valid state. + +#### Using pytest {#using-pytest} + +Pytest is the most common test runner for python repositories. A trivial +test run would be: + +``` + checkInputs = [ pytest ]; + checkPhase = "pytest"; +``` + +However, many repositories' test suites do not translate well to nix's build +sandbox, and will generally need many tests to be disabled. + +To filter tests using pytest, one can do the following: + +``` + checkInputs = [ pytest ]; + # avoid tests which need additional data or touch network + checkPhase = '' + pytest tests/ --ignore=tests/integration -k 'not download and not update' + ''; +``` + +`--ignore` will tell pytest to ignore that file or directory from being +collected as part of a test run. This is useful is a file uses a package +which is not available in nixpkgs, thus skipping that test file is much +easier than having to create a new package. + +`-k` is used to define a predicate for test names. In this example, we are +filtering out tests which contain `download` or `update` in their test case name. +Only one `-k` argument is allowed, and thus a long predicate should be concatenated +with “\\” and wrapped to the next line. + +*NOTE:* In pytest==6.0.1, the use of “\\” to continue a line (e.g. `-k 'not download \'`) has +been removed, in this case, it's recommended to use `pytestCheckHook`. + +#### Using pytestCheckHook {#using-pytestcheckhook} + +`pytestCheckHook` is a convenient hook which will substitute the setuptools +`test` command for a checkPhase which runs `pytest`. This is also beneficial +when a package may need many items disabled to run the test suite. + +Using the example above, the analagous pytestCheckHook usage would be: + +``` + checkInputs = [ pytestCheckHook ]; + + # requires additional data + pytestFlagsArray = [ "tests/" "--ignore=tests/integration" ]; + + disabledTests = [ + # touches network + "download" + "update" + ]; + + disabledTestPaths = [ + "tests/test_failing.py" + ]; +``` + +This is expecially useful when tests need to be conditionallydisabled, +for example: + +``` + disabledTests = [ + # touches network + "download" + "update" + ] ++ lib.optionals (pythonAtLeast "3.8") [ + # broken due to python3.8 async changes + "async" + ] ++ lib.optionals stdenv.isDarwin [ + # can fail when building with other packages + "socket" + ]; +``` +Trying to concatenate the related strings to disable tests in a regular checkPhase +would be much harder to read. This also enables us to comment on why specific tests +are disabled. + +#### Using pythonImportsCheck {#using-pythonimportscheck} + +Although unit tests are highly prefered to validate correctness of a package, not +all packages have test suites that can be ran easily, and some have none at all. +To help ensure the package still works, `pythonImportsCheck` can attempt to import +the listed modules. + +``` + pythonImportsCheck = [ "requests" "urllib" ]; +``` +roughly translates to: +``` + postCheck = '' + PYTHONPATH=$out/${python.sitePackages}:$PYTHONPATH + python -c "import requests; import urllib" + ''; +``` +However, this is done in it's own phase, and not dependent on whether `doCheck = true;` + +This can also be useful in verifying that the package doesn't assume commonly +present packages (e.g. `setuptools`) + +### Develop local package {#develop-local-package} + +As a Python developer you're likely aware of [development mode](http://setuptools.readthedocs.io/en/latest/setuptools.html#development-mode) +(`python setup.py develop`); instead of installing the package this command +creates a special link to the project code. That way, you can run updated code +without having to reinstall after each and every change you make. Development +mode is also available. Let's see how you can use it. + +In the previous Nix expression the source was fetched from an url. We can also +refer to a local source instead using `src = ./path/to/source/tree;` + +If we create a `shell.nix` file which calls `buildPythonPackage`, and if `src` +is a local source, and if the local source has a `setup.py`, then development +mode is activated. + +In the following example we create a simple environment that has a Python 3.8 +version of our package in it, as well as its dependencies and other packages we +like to have in the environment, all specified with `propagatedBuildInputs`. +Indeed, we can just add any package we like to have in our environment to +`propagatedBuildInputs`. + +```nix +with import <nixpkgs> {}; +with python38Packages; + +buildPythonPackage rec { + name = "mypackage"; + src = ./path/to/package/source; + propagatedBuildInputs = [ pytest numpy pkgs.libsndfile ]; +} +``` + +It is important to note that due to how development mode is implemented on Nix +it is not possible to have multiple packages simultaneously in development mode. + +### Organising your packages {#organising-your-packages} + +So far we discussed how you can use Python on Nix, and how you can develop with +it. We've looked at how you write expressions to package Python packages, and we +looked at how you can create environments in which specified packages are +available. + +At some point you'll likely have multiple packages which you would +like to be able to use in different projects. In order to minimise unnecessary +duplication we now look at how you can maintain a repository with your +own packages. The important functions here are `import` and `callPackage`. + +### Including a derivation using `callPackage` {#including-a-derivation-using-callpackage} + +Earlier we created a Python environment using `withPackages`, and included the +`toolz` package via a `let` expression. +Let's split the package definition from the environment definition. + +We first create a function that builds `toolz` in `~/path/to/toolz/release.nix` + +```nix +{ lib, buildPythonPackage }: + +buildPythonPackage rec { + pname = "toolz"; + version = "0.10.0"; + + src = fetchPypi { + inherit pname version; + sha256 = "08fdd5ef7c96480ad11c12d472de21acd32359996f69a5259299b540feba4560"; + }; + + meta = with lib; { + homepage = "https://github.com/pytoolz/toolz/"; + description = "List processing tools and functional utilities"; + license = licenses.bsd3; + maintainers = with maintainers; [ fridh ]; + }; +} +``` + +It takes an argument `buildPythonPackage`. We now call this function using +`callPackage` in the definition of our environment + +```nix +with import <nixpkgs> {}; + +( let + toolz = callPackage /path/to/toolz/release.nix { + buildPythonPackage = python38Packages.buildPythonPackage; + }; + in python38.withPackages (ps: [ ps.numpy toolz ]) +).env +``` + +Important to remember is that the Python version for which the package is made +depends on the `python` derivation that is passed to `buildPythonPackage`. Nix +tries to automatically pass arguments when possible, which is why generally you +don't explicitly define which `python` derivation should be used. In the above +example we use `buildPythonPackage` that is part of the set `python38Packages`, +and in this case the `python38` interpreter is automatically used. + +## Reference {#reference} + +### Interpreters {#interpreters} + +Versions 2.7, 3.7, 3.8 and 3.9 of the CPython interpreter are available as +respectively `python27`, `python37`, `python38` and `python39`. The +aliases `python2` and `python3` correspond to respectively `python27` and +`python39`. The attribute `python` maps to `python2`. The PyPy interpreters +compatible with Python 2.7 and 3 are available as `pypy27` and `pypy3`, with +aliases `pypy2` mapping to `pypy27` and `pypy` mapping to `pypy2`. The Nix +expressions for the interpreters can be found in +`pkgs/development/interpreters/python`. + +All packages depending on any Python interpreter get appended +`out/{python.sitePackages}` to `$PYTHONPATH` if such directory +exists. + +#### Missing `tkinter` module standard library {#missing-tkinter-module-standard-library} + +To reduce closure size the `Tkinter`/`tkinter` is available as a separate package, `pythonPackages.tkinter`. + +#### Attributes on interpreters packages {#attributes-on-interpreters-packages} + +Each interpreter has the following attributes: + +- `libPrefix`. Name of the folder in `${python}/lib/` for corresponding interpreter. +- `interpreter`. Alias for `${python}/bin/${executable}`. +- `buildEnv`. Function to build python interpreter environments with extra packages bundled together. See section *python.buildEnv function* for usage and documentation. +- `withPackages`. Simpler interface to `buildEnv`. See section *python.withPackages function* for usage and documentation. +- `sitePackages`. Alias for `lib/${libPrefix}/site-packages`. +- `executable`. Name of the interpreter executable, e.g. `python3.8`. +- `pkgs`. Set of Python packages for that specific interpreter. The package set can be modified by overriding the interpreter and passing `packageOverrides`. + +### Optimizations {#optimizations} + +The Python interpreters are by default not build with optimizations enabled, because +the builds are in that case not reproducible. To enable optimizations, override the +interpreter of interest, e.g using + +``` +let + pkgs = import ./. {}; + mypython = pkgs.python3.override { + enableOptimizations = true; + reproducibleBuild = false; + self = mypython; + }; +in mypython +``` + +### Building packages and applications {#building-packages-and-applications} + +Python libraries and applications that use `setuptools` or +`distutils` are typically built with respectively the `buildPythonPackage` and +`buildPythonApplication` functions. These two functions also support installing a `wheel`. + +All Python packages reside in `pkgs/top-level/python-packages.nix` and all +applications elsewhere. In case a package is used as both a library and an +application, then the package should be in `pkgs/top-level/python-packages.nix` +since only those packages are made available for all interpreter versions. The +preferred location for library expressions is in +`pkgs/development/python-modules`. It is important that these packages are +called from `pkgs/top-level/python-packages.nix` and not elsewhere, to guarantee +the right version of the package is built. + +Based on the packages defined in `pkgs/top-level/python-packages.nix` an +attribute set is created for each available Python interpreter. The available +sets are + +* `pkgs.python27Packages` +* `pkgs.python37Packages` +* `pkgs.python38Packages` +* `pkgs.python39Packages` +* `pkgs.python310Packages` +* `pkgs.python311Packages` +* `pkgs.pypyPackages` + +and the aliases + +* `pkgs.python2Packages` pointing to `pkgs.python27Packages` +* `pkgs.python3Packages` pointing to `pkgs.python39Packages` +* `pkgs.pythonPackages` pointing to `pkgs.python2Packages` + +#### `buildPythonPackage` function {#buildpythonpackage-function} + +The `buildPythonPackage` function is implemented in +`pkgs/development/interpreters/python/mk-python-derivation` +using setup hooks. + +The following is an example: + +```nix +{ lib, buildPythonPackage, fetchPypi, hypothesis, setuptools-scm, attrs, py, setuptools, six, pluggy }: + +buildPythonPackage rec { + pname = "pytest"; + version = "3.3.1"; + + src = fetchPypi { + inherit pname version; + sha256 = "cf8436dc59d8695346fcd3ab296de46425ecab00d64096cebe79fb51ecb2eb93"; + }; + + postPatch = '' + # don't test bash builtins + rm testing/test_argcomplete.py + ''; + + checkInputs = [ hypothesis ]; + nativeBuildInputs = [ setuptools-scm ]; + propagatedBuildInputs = [ attrs py setuptools six pluggy ]; + + meta = with lib; { + maintainers = with maintainers; [ domenkozar lovek323 madjar lsix ]; + description = "Framework for writing tests"; + }; +} +``` + +The `buildPythonPackage` mainly does four things: + +* In the `buildPhase`, it calls `${python.interpreter} setup.py bdist_wheel` to + build a wheel binary zipfile. +* In the `installPhase`, it installs the wheel file using `pip install *.whl`. +* In the `postFixup` phase, the `wrapPythonPrograms` bash function is called to + wrap all programs in the `$out/bin/*` directory to include `$PATH` + environment variable and add dependent libraries to script's `sys.path`. +* In the `installCheck` phase, `${python.interpreter} setup.py test` is ran. + +By default tests are run because `doCheck = true`. Test dependencies, like +e.g. the test runner, should be added to `checkInputs`. + +By default `meta.platforms` is set to the same value +as the interpreter unless overridden otherwise. + +##### `buildPythonPackage` parameters {#buildpythonpackage-parameters} + +All parameters from `stdenv.mkDerivation` function are still supported. The +following are specific to `buildPythonPackage`: + +* `catchConflicts ? true`: If `true`, abort package build if a package name + appears more than once in dependency tree. Default is `true`. +* `disabled` ? false: If `true`, package is not built for the particular Python + interpreter version. +* `dontWrapPythonPrograms ? false`: Skip wrapping of Python programs. +* `permitUserSite ? false`: Skip setting the `PYTHONNOUSERSITE` environment + variable in wrapped programs. +* `format ? "setuptools"`: Format of the source. Valid options are + `"setuptools"`, `"pyproject"`, `"flit"`, `"wheel"`, and `"other"`. + `"setuptools"` is for when the source has a `setup.py` and `setuptools` is + used to build a wheel, `flit`, in case `flit` should be used to build a wheel, + and `wheel` in case a wheel is provided. Use `other` when a custom + `buildPhase` and/or `installPhase` is needed. +* `makeWrapperArgs ? []`: A list of strings. Arguments to be passed to + `makeWrapper`, which wraps generated binaries. By default, the arguments to + `makeWrapper` set `PATH` and `PYTHONPATH` environment variables before calling + the binary. Additional arguments here can allow a developer to set environment + variables which will be available when the binary is run. For example, + `makeWrapperArgs = ["--set FOO BAR" "--set BAZ QUX"]`. +* `namePrefix`: Prepends text to `${name}` parameter. In case of libraries, this + defaults to `"python3.8-"` for Python 3.8, etc., and in case of applications + to `""`. +* `pipInstallFlags ? []`: A list of strings. Arguments to be passed to `pip + install`. To pass options to `python setup.py install`, use + `--install-option`. E.g., `pipInstallFlags=["--install-option='--cpp_implementation'"]`. +* `pythonPath ? []`: List of packages to be added into `$PYTHONPATH`. Packages + in `pythonPath` are not propagated (contrary to `propagatedBuildInputs`). +* `preShellHook`: Hook to execute commands before `shellHook`. +* `postShellHook`: Hook to execute commands after `shellHook`. +* `removeBinByteCode ? true`: Remove bytecode from `/bin`. Bytecode is only + created when the filenames end with `.py`. +* `setupPyGlobalFlags ? []`: List of flags passed to `setup.py` command. +* `setupPyBuildFlags ? []`: List of flags passed to `setup.py build_ext` command. + +The `stdenv.mkDerivation` function accepts various parameters for describing +build inputs (see "Specifying dependencies"). The following are of special +interest for Python packages, either because these are primarily used, or +because their behaviour is different: + +* `nativeBuildInputs ? []`: Build-time only dependencies. Typically executables + as well as the items listed in `setup_requires`. +* `buildInputs ? []`: Build and/or run-time dependencies that need to be + compiled for the host machine. Typically non-Python libraries which are being + linked. +* `checkInputs ? []`: Dependencies needed for running the `checkPhase`. These + are added to `nativeBuildInputs` when `doCheck = true`. Items listed in + `tests_require` go here. +* `propagatedBuildInputs ? []`: Aside from propagating dependencies, + `buildPythonPackage` also injects code into and wraps executables with the + paths included in this list. Items listed in `install_requires` go here. + +##### Overriding Python packages {#overriding-python-packages} + +The `buildPythonPackage` function has a `overridePythonAttrs` method that can be +used to override the package. In the following example we create an environment +where we have the `blaze` package using an older version of `pandas`. We +override first the Python interpreter and pass `packageOverrides` which contains +the overrides for packages in the package set. + +```nix +with import <nixpkgs> {}; + +(let + python = let + packageOverrides = self: super: { + pandas = super.pandas.overridePythonAttrs(old: rec { + version = "0.19.1"; + src = super.fetchPypi { + pname = "pandas"; + inherit version; + sha256 = "08blshqj9zj1wyjhhw3kl2vas75vhhicvv72flvf1z3jvapgw295"; + }; + }); + }; + in pkgs.python3.override {inherit packageOverrides; self = python;}; + +in python.withPackages(ps: [ps.blaze])).env +``` + +#### Optional extra dependencies + +Some packages define optional dependencies for additional features. With +`setuptools` this is called `extras_require` and `flit` calls it `extras-require`. A +method for supporting this is by declaring the extras of a package in its +`passthru`, e.g. in case of the package `dask` + +```nix +passthru.extras-require = { + complete = [ distributed ]; +}; +``` + +and letting the package requiring the extra add the list to its dependencies + +```nix +propagatedBuildInputs = [ + ... +] ++ dask.extras-require.complete; +``` + +Note this method is preferred over adding parameters to builders, as that can +result in packages depending on different variants and thereby causing +collisions. + +#### `buildPythonApplication` function {#buildpythonapplication-function} + +The `buildPythonApplication` function is practically the same as +`buildPythonPackage`. The main purpose of this function is to build a Python +package where one is interested only in the executables, and not importable +modules. For that reason, when adding this package to a `python.buildEnv`, the +modules won't be made available. + +Another difference is that `buildPythonPackage` by default prefixes the names of +the packages with the version of the interpreter. Because this is irrelevant for +applications, the prefix is omitted. + +When packaging a Python application with `buildPythonApplication`, it should be +called with `callPackage` and passed `python` or `pythonPackages` (possibly +specifying an interpreter version), like this: + +```nix +{ lib, python3 }: + +python3.pkgs.buildPythonApplication rec { + pname = "luigi"; + version = "2.7.9"; + + src = python3.pkgs.fetchPypi { + inherit pname version; + sha256 = "035w8gqql36zlan0xjrzz9j4lh9hs0qrsgnbyw07qs7lnkvbdv9x"; + }; + + propagatedBuildInputs = with python3.pkgs; [ tornado python-daemon ]; + + meta = with lib; { + ... + }; +} +``` + +This is then added to `all-packages.nix` just as any other application would be. + +```nix +luigi = callPackage ../applications/networking/cluster/luigi { }; +``` + +Since the package is an application, a consumer doesn't need to care about +Python versions or modules, which is why they don't go in `pythonPackages`. + +#### `toPythonApplication` function {#topythonapplication-function} + +A distinction is made between applications and libraries, however, sometimes a +package is used as both. In this case the package is added as a library to +`python-packages.nix` and as an application to `all-packages.nix`. To reduce +duplication the `toPythonApplication` can be used to convert a library to an +application. + +The Nix expression shall use `buildPythonPackage` and be called from +`python-packages.nix`. A reference shall be created from `all-packages.nix` to +the attribute in `python-packages.nix`, and the `toPythonApplication` shall be +applied to the reference: + +```nix +youtube-dl = with pythonPackages; toPythonApplication youtube-dl; +``` + +#### `toPythonModule` function {#topythonmodule-function} + +In some cases, such as bindings, a package is created using +`stdenv.mkDerivation` and added as attribute in `all-packages.nix`. The Python +bindings should be made available from `python-packages.nix`. The +`toPythonModule` function takes a derivation and makes certain Python-specific +modifications. + +```nix +opencv = toPythonModule (pkgs.opencv.override { + enablePython = true; + pythonPackages = self; +}); +``` + +Do pay attention to passing in the right Python version! + +#### `python.buildEnv` function {#python.buildenv-function} + +Python environments can be created using the low-level `pkgs.buildEnv` function. +This example shows how to create an environment that has the Pyramid Web Framework. +Saving the following as `default.nix` + +```nix +with import <nixpkgs> {}; + +python.buildEnv.override { + extraLibs = [ pythonPackages.pyramid ]; + ignoreCollisions = true; +} +``` + +and running `nix-build` will create + +``` +/nix/store/cf1xhjwzmdki7fasgr4kz6di72ykicl5-python-2.7.8-env +``` + +with wrapped binaries in `bin/`. + +You can also use the `env` attribute to create local environments with needed +packages installed. This is somewhat comparable to `virtualenv`. For example, +running `nix-shell` with the following `shell.nix` + +```nix +with import <nixpkgs> {}; + +(python3.buildEnv.override { + extraLibs = with python3Packages; [ numpy requests ]; +}).env +``` + +will drop you into a shell where Python will have the +specified packages in its path. + +##### `python.buildEnv` arguments {#python.buildenv-arguments} + + +* `extraLibs`: List of packages installed inside the environment. +* `postBuild`: Shell command executed after the build of environment. +* `ignoreCollisions`: Ignore file collisions inside the environment (default is `false`). +* `permitUserSite`: Skip setting the `PYTHONNOUSERSITE` environment variable in + wrapped binaries in the environment. + +#### `python.withPackages` function {#python.withpackages-function} + +The `python.withPackages` function provides a simpler interface to the `python.buildEnv` functionality. +It takes a function as an argument that is passed the set of python packages and returns the list +of the packages to be included in the environment. Using the `withPackages` function, the previous +example for the Pyramid Web Framework environment can be written like this: + +```nix +with import <nixpkgs> {}; + +python.withPackages (ps: [ps.pyramid]) +``` + +`withPackages` passes the correct package set for the specific interpreter +version as an argument to the function. In the above example, `ps` equals +`pythonPackages`. But you can also easily switch to using python3: + +```nix +with import <nixpkgs> {}; + +python3.withPackages (ps: [ps.pyramid]) +``` + +Now, `ps` is set to `python3Packages`, matching the version of the interpreter. + +As `python.withPackages` simply uses `python.buildEnv` under the hood, it also +supports the `env` attribute. The `shell.nix` file from the previous section can +thus be also written like this: + +```nix +with import <nixpkgs> {}; + +(python38.withPackages (ps: [ps.numpy ps.requests])).env +``` + +In contrast to `python.buildEnv`, `python.withPackages` does not support the +more advanced options such as `ignoreCollisions = true` or `postBuild`. If you +need them, you have to use `python.buildEnv`. + +Python 2 namespace packages may provide `__init__.py` that collide. In that case +`python.buildEnv` should be used with `ignoreCollisions = true`. + +#### Setup hooks {#setup-hooks} + +The following are setup hooks specifically for Python packages. Most of these +are used in `buildPythonPackage`. + +- `eggUnpackhook` to move an egg to the correct folder so it can be installed + with the `eggInstallHook` +- `eggBuildHook` to skip building for eggs. +- `eggInstallHook` to install eggs. +- `flitBuildHook` to build a wheel using `flit`. +- `pipBuildHook` to build a wheel using `pip` and PEP 517. Note a build system + (e.g. `setuptools` or `flit`) should still be added as `nativeBuildInput`. +- `pipInstallHook` to install wheels. +- `pytestCheckHook` to run tests with `pytest`. See [example usage](#using-pytestcheckhook). +- `pythonCatchConflictsHook` to check whether a Python package is not already existing. +- `pythonImportsCheckHook` to check whether importing the listed modules works. +- `pythonRemoveBinBytecode` to remove bytecode from the `/bin` folder. +- `setuptoolsBuildHook` to build a wheel using `setuptools`. +- `setuptoolsCheckHook` to run tests with `python setup.py test`. +- `venvShellHook` to source a Python 3 `venv` at the `venvDir` location. A + `venv` is created if it does not yet exist. `postVenvCreation` can be used to + to run commands only after venv is first created. +- `wheelUnpackHook` to move a wheel to the correct folder so it can be installed + with the `pipInstallHook`. + +### Development mode {#development-mode} + +Development or editable mode is supported. To develop Python packages +`buildPythonPackage` has additional logic inside `shellPhase` to run `pip +install -e . --prefix $TMPDIR/`for the package. + +Warning: `shellPhase` is executed only if `setup.py` exists. + +Given a `default.nix`: + +```nix +with import <nixpkgs> {}; + +pythonPackages.buildPythonPackage { + name = "myproject"; + buildInputs = with pythonPackages; [ pyramid ]; + + src = ./.; +} +``` + +Running `nix-shell` with no arguments should give you the environment in which +the package would be built with `nix-build`. + +Shortcut to setup environments with C headers/libraries and Python packages: + +```shell +nix-shell -p pythonPackages.pyramid zlib libjpeg git +``` + +Note: There is a boolean value `lib.inNixShell` set to `true` if nix-shell is invoked. + +### Tools {#tools} + +Packages inside nixpkgs are written by hand. However many tools exist in +community to help save time. No tool is preferred at the moment. + +- [pypi2nix](https://github.com/nix-community/pypi2nix): Generate Nix + expressions for your Python project. Note that [sharing derivations from + pypi2nix with nixpkgs is possible but not + encouraged](https://github.com/nix-community/pypi2nix/issues/222#issuecomment-443497376). +- [nixpkgs-pytools](https://github.com/nix-community/nixpkgs-pytools) +- [poetry2nix](https://github.com/nix-community/poetry2nix) + +### Deterministic builds {#deterministic-builds} + +The Python interpreters are now built deterministically. Minor modifications had +to be made to the interpreters in order to generate deterministic bytecode. This +has security implications and is relevant for those using Python in a +`nix-shell`. + +When the environment variable `DETERMINISTIC_BUILD` is set, all bytecode will +have timestamp 1. The `buildPythonPackage` function sets `DETERMINISTIC_BUILD=1` +and [PYTHONHASHSEED=0](https://docs.python.org/3.8/using/cmdline.html#envvar-PYTHONHASHSEED). +Both are also exported in `nix-shell`. + +### Automatic tests {#automatic-tests} + +It is recommended to test packages as part of the build process. +Source distributions (`sdist`) often include test files, but not always. + +By default the command `python setup.py test` is run as part of the +`checkPhase`, but often it is necessary to pass a custom `checkPhase`. An +example of such a situation is when `py.test` is used. + +#### Common issues {#common-issues} + +* Non-working tests can often be deselected. By default `buildPythonPackage` + runs `python setup.py test`. Most Python modules follows the standard test + protocol where the pytest runner can be used instead. `py.test` supports a + `-k` parameter to ignore test methods or classes: + + ```nix + buildPythonPackage { + # ... + # assumes the tests are located in tests + checkInputs = [ pytest ]; + checkPhase = '' + py.test -k 'not function_name and not other_function' tests + ''; + } + ``` + +* Tests that attempt to access `$HOME` can be fixed by using the following + work-around before running tests (e.g. `preCheck`): `export HOME=$(mktemp -d)` + +## FAQ {#faq} + +### How to solve circular dependencies? {#how-to-solve-circular-dependencies} + +Consider the packages `A` and `B` that depend on each other. When packaging `B`, +a solution is to override package `A` not to depend on `B` as an input. The same +should also be done when packaging `A`. + +### How to override a Python package? {#how-to-override-a-python-package} + +We can override the interpreter and pass `packageOverrides`. In the following +example we rename the `pandas` package and build it. + +```nix +with import <nixpkgs> {}; + +(let + python = let + packageOverrides = self: super: { + pandas = super.pandas.overridePythonAttrs(old: {name="foo";}); + }; + in pkgs.python38.override {inherit packageOverrides;}; + +in python.withPackages(ps: [ps.pandas])).env +``` + +Using `nix-build` on this expression will build an environment that contains the +package `pandas` but with the new name `foo`. + +All packages in the package set will use the renamed package. A typical use case +is to switch to another version of a certain package. For example, in the +Nixpkgs repository we have multiple versions of `django` and `scipy`. In the +following example we use a different version of `scipy` and create an +environment that uses it. All packages in the Python package set will now use +the updated `scipy` version. + +```nix +with import <nixpkgs> {}; + +( let + packageOverrides = self: super: { + scipy = super.scipy_0_17; + }; + in (pkgs.python38.override {inherit packageOverrides;}).withPackages (ps: [ps.blaze]) +).env +``` + +The requested package `blaze` depends on `pandas` which itself depends on `scipy`. + +If you want the whole of Nixpkgs to use your modifications, then you can use +`overlays` as explained in this manual. In the following example we build a +`inkscape` using a different version of `numpy`. + +```nix +let + pkgs = import <nixpkgs> {}; + newpkgs = import pkgs.path { overlays = [ (self: super: { + python38 = let + packageOverrides = python-self: python-super: { + numpy = python-super.numpy_1_18; + }; + in super.python38.override {inherit packageOverrides;}; + } ) ]; }; +in newpkgs.inkscape +``` + +### `python setup.py bdist_wheel` cannot create .whl {#python-setup.py-bdist_wheel-cannot-create-.whl} + +Executing `python setup.py bdist_wheel` in a `nix-shell `fails with +``` +ValueError: ZIP does not support timestamps before 1980 +``` + +This is because files from the Nix store (which have a timestamp of the UNIX +epoch of January 1, 1970) are included in the .ZIP, but .ZIP archives follow the +DOS convention of counting timestamps from 1980. + +The command `bdist_wheel` reads the `SOURCE_DATE_EPOCH` environment variable, +which `nix-shell` sets to 1. Unsetting this variable or giving it a value +corresponding to 1980 or later enables building wheels. + +Use 1980 as timestamp: + +```shell +nix-shell --run "SOURCE_DATE_EPOCH=315532800 python3 setup.py bdist_wheel" +``` + +or the current time: + +```shell +nix-shell --run "SOURCE_DATE_EPOCH=$(date +%s) python3 setup.py bdist_wheel" +``` + +or unset `SOURCE_DATE_EPOCH`: + +```shell +nix-shell --run "unset SOURCE_DATE_EPOCH; python3 setup.py bdist_wheel" +``` + +### `install_data` / `data_files` problems {#install_data-data_files-problems} + +If you get the following error: + +``` +could not create '/nix/store/6l1bvljpy8gazlsw2aw9skwwp4pmvyxw-python-2.7.8/etc': +Permission denied +``` + +This is a [known bug](https://github.com/pypa/setuptools/issues/130) in +`setuptools`. Setuptools `install_data` does not respect `--prefix`. An example +of such package using the feature is `pkgs/tools/X11/xpra/default.nix`. + +As workaround install it as an extra `preInstall` step: + +```shell +${python.interpreter} setup.py install_data --install-dir=$out --root=$out +sed -i '/ = data\_files/d' setup.py +``` + +### Rationale of non-existent global site-packages {#rationale-of-non-existent-global-site-packages} + +On most operating systems a global `site-packages` is maintained. This however +becomes problematic if you want to run multiple Python versions or have multiple +versions of certain libraries for your projects. Generally, you would solve such +issues by creating virtual environments using `virtualenv`. + +On Nix each package has an isolated dependency tree which, in the case of +Python, guarantees the right versions of the interpreter and libraries or +packages are available. There is therefore no need to maintain a global `site-packages`. + +If you want to create a Python environment for development, then the recommended +method is to use `nix-shell`, either with or without the `python.buildEnv` +function. + +### How to consume Python modules using pip in a virtual environment like I am used to on other Operating Systems? {#how-to-consume-python-modules-using-pip-in-a-virtual-environment-like-i-am-used-to-on-other-operating-systems} + +While this approach is not very idiomatic from Nix perspective, it can still be +useful when dealing with pre-existing projects or in situations where it's not +feasible or desired to write derivations for all required dependencies. + +This is an example of a `default.nix` for a `nix-shell`, which allows to consume +a virtual environment created by `venv`, and install Python modules through +`pip` the traditional way. + +Create this `default.nix` file, together with a `requirements.txt` and simply +execute `nix-shell`. + +```nix +with import <nixpkgs> { }; + +let + pythonPackages = python3Packages; +in pkgs.mkShell rec { + name = "impurePythonEnv"; + venvDir = "./.venv"; + buildInputs = [ + # A Python interpreter including the 'venv' module is required to bootstrap + # the environment. + pythonPackages.python + + # This execute some shell code to initialize a venv in $venvDir before + # dropping into the shell + pythonPackages.venvShellHook + + # Those are dependencies that we would like to use from nixpkgs, which will + # add them to PYTHONPATH and thus make them accessible from within the venv. + pythonPackages.numpy + pythonPackages.requests + + # In this particular example, in order to compile any binary extensions they may + # require, the Python modules listed in the hypothetical requirements.txt need + # the following packages to be installed locally: + taglib + openssl + git + libxml2 + libxslt + libzip + zlib + ]; + + # Run this command, only after creating the virtual environment + postVenvCreation = '' + unset SOURCE_DATE_EPOCH + pip install -r requirements.txt + ''; + + # Now we can execute any commands within the virtual environment. + # This is optional and can be left out to run pip manually. + postShellHook = '' + # allow pip to install wheels + unset SOURCE_DATE_EPOCH + ''; + +} +``` + +In case the supplied venvShellHook is insufficient, or when Python 2 support is +needed, you can define your own shell hook and adapt to your needs like in the +following example: + +```nix +with import <nixpkgs> { }; + +let + venvDir = "./.venv"; + pythonPackages = python3Packages; +in pkgs.mkShell rec { + name = "impurePythonEnv"; + buildInputs = [ + pythonPackages.python + # Needed when using python 2.7 + # pythonPackages.virtualenv + # ... + ]; + + # This is very close to how venvShellHook is implemented, but + # adapted to use 'virtualenv' + shellHook = '' + SOURCE_DATE_EPOCH=$(date +%s) + + if [ -d "${venvDir}" ]; then + echo "Skipping venv creation, '${venvDir}' already exists" + else + echo "Creating new venv environment in path: '${venvDir}'" + # Note that the module venv was only introduced in python 3, so for 2.7 + # this needs to be replaced with a call to virtualenv + ${pythonPackages.python.interpreter} -m venv "${venvDir}" + fi + + # Under some circumstances it might be necessary to add your virtual + # environment to PYTHONPATH, which you can do here too; + # PYTHONPATH=$PWD/${venvDir}/${pythonPackages.python.sitePackages}/:$PYTHONPATH + + source "${venvDir}/bin/activate" + + # As in the previous example, this is optional. + pip install -r requirements.txt + ''; +} +``` + +Note that the `pip install` is an imperative action. So every time `nix-shell` +is executed it will attempt to download the Python modules listed in +requirements.txt. However these will be cached locally within the `virtualenv` +folder and not downloaded again. + +### How to override a Python package from `configuration.nix`? {#how-to-override-a-python-package-from-configuration.nix} + +If you need to change a package's attribute(s) from `configuration.nix` you could do: + +```nix + nixpkgs.config.packageOverrides = super: { + python = super.python.override { + packageOverrides = python-self: python-super: { + twisted = python-super.twisted.overrideAttrs (oldAttrs: { + src = super.fetchPypi { + pname = "twisted"; + version = "19.10.0"; + sha256 = "7394ba7f272ae722a74f3d969dcf599bc4ef093bc392038748a490f1724a515d"; + extension = "tar.bz2"; + }; + }); + }; + }; + }; +``` + +`pythonPackages.twisted` is now globally overridden. +All packages and also all NixOS services that reference `twisted` +(such as `services.buildbot-worker`) now use the new definition. +Note that `python-super` refers to the old package set and `python-self` +to the new, overridden version. + +To modify only a Python package set instead of a whole Python derivation, use +this snippet: + +```nix + myPythonPackages = pythonPackages.override { + overrides = self: super: { + twisted = ...; + }; + } +``` + +### How to override a Python package using overlays? {#how-to-override-a-python-package-using-overlays} + +Use the following overlay template: + +```nix +self: super: { + python = super.python.override { + packageOverrides = python-self: python-super: { + twisted = python-super.twisted.overrideAttrs (oldAttrs: { + src = super.fetchPypi { + pname = "twisted"; + version = "19.10.0"; + sha256 = "7394ba7f272ae722a74f3d969dcf599bc4ef093bc392038748a490f1724a515d"; + extension = "tar.bz2"; + }; + }); + }; + }; +} +``` + +### How to use Intel’s MKL with numpy and scipy? {#how-to-use-intels-mkl-with-numpy-and-scipy} + +MKL can be configured using an overlay. See the section "[Using overlays to +configure alternatives](#sec-overlays-alternatives-blas-lapack)". + +### What inputs do `setup_requires`, `install_requires` and `tests_require` map to? {#what-inputs-do-setup_requires-install_requires-and-tests_require-map-to} + +In a `setup.py` or `setup.cfg` it is common to declare dependencies: + +* `setup_requires` corresponds to `nativeBuildInputs` +* `install_requires` corresponds to `propagatedBuildInputs` +* `tests_require` corresponds to `checkInputs` + +## Contributing {#contributing} + +### Contributing guidelines {#contributing-guidelines} + +The following rules are desired to be respected: + +* Python libraries are called from `python-packages.nix` and packaged with + `buildPythonPackage`. The expression of a library should be in + `pkgs/development/python-modules/<name>/default.nix`. +* Python applications live outside of `python-packages.nix` and are packaged + with `buildPythonApplication`. +* Make sure libraries build for all Python interpreters. +* By default we enable tests. Make sure the tests are found and, in the case of + libraries, are passing for all interpreters. If certain tests fail they can be + disabled individually. Try to avoid disabling the tests altogether. In any + case, when you disable tests, leave a comment explaining why. +* Commit names of Python libraries should reflect that they are Python + libraries, so write for example `pythonPackages.numpy: 1.11 -> 1.12`. +* Attribute names in `python-packages.nix` as well as `pname`s should match the + library's name on PyPI, but be normalized according to [PEP + 0503](https://www.python.org/dev/peps/pep-0503/#normalized-names). This means + that characters should be converted to lowercase and `.` and `_` should be + replaced by a single `-` (foo-bar-baz instead of Foo__Bar.baz). + If necessary, `pname` has to be given a different value within `fetchPypi`. +* Attribute names in `python-packages.nix` should be sorted alphanumerically to + avoid merge conflicts and ease locating attributes. + +## Package set maintenance + +The whole Python package set has a lot of packages that do not see regular +updates, because they either are a very fragile component in the Python +ecosystem, like for example the `hypothesis` package, or packages that have +no maintainer, so maintenance falls back to the package set maintainers. + +### Updating packages in bulk + +There is a tool to update alot of python libraries in bulk, it exists at +`maintainers/scripts/update-python-libraries` with this repository. + +It can quickly update minor or major versions for all packages selected +and create update commits, and supports the `fetchPypi`, `fetchurl` and +`fetchFromGitHub` fetchers. When updating lots of packages that are +hosted on GitHub, exporting a `GITHUB_API_TOKEN` is highly recommended. + +Updating packages in bulk leads to lots of breakages, which is why a +stabilization period on the `python-unstable` branch is required. + +Once the branch is sufficiently stable it should normally be merged +into the `staging` branch. + +An exemplary call to update all python libraries between minor versions +would be: + +```ShellSession +$ maintainers/scripts/update-python-libraries --target minor --commit --use-pkgs-prefix pkgs/development/python-modules/**/default.nix +``` + +## CPython Update Schedule + +With [PEP 602](https://www.python.org/dev/peps/pep-0602/), CPython now +follows a yearly release cadence. In nixpkgs, all supported interpreters +are made available, but only the most recent two +interpreters package sets are built; this is a compromise between being +the latest interpreter, and what the majority of the Python packages support. + +New CPython interpreters are released in October. Generally, it takes some +time for the majority of active Python projects to support the latest stable +interpreter. To help ease the migration for Nixpkgs users +between Python interpreters the schedule below will be used: + +| When | Event | +| --- | --- | +| After YY.11 Release | Bump CPython package set window. The latest and previous latest stable should now be built. | +| After YY.05 Release | Bump default CPython interpreter to latest stable. | + +In practice, this means that the Python community will have had a stable interpreter +for ~2 months before attempting to update the package set. And this will +allow for ~7 months for Python applications to support the latest interpreter. diff --git a/doc/languages-frameworks/qt.section.md b/doc/languages-frameworks/qt.section.md new file mode 100644 index 00000000000..986deeb0d4b --- /dev/null +++ b/doc/languages-frameworks/qt.section.md @@ -0,0 +1,160 @@ +# Qt {#sec-language-qt} + +Writing Nix expressions for Qt libraries and applications is largely similar as for other C++ software. +This section assumes some knowledge of the latter. +There are two problems that the Nixpkgs Qt infrastructure addresses, +which are not shared by other C++ software: + +1. There are usually multiple supported versions of Qt in Nixpkgs. + All of a package's dependencies must be built with the same version of Qt. + This is similar to the version constraints imposed on interpreted languages like Python. +2. Qt makes extensive use of runtime dependency detection. + Runtime dependencies are made into build dependencies through wrappers. + +## Nix expression for a Qt package (default.nix) {#qt-default-nix} + +```{=docbook} +<programlisting> +{ stdenv, lib, qtbase, wrapQtAppsHook }: <co xml:id='qt-default-nix-co-1' /> + +stdenv.mkDerivation { + pname = "myapp"; + version = "1.0"; + + buildInputs = [ qtbase ]; + nativeBuildInputs = [ wrapQtAppsHook ]; <co xml:id='qt-default-nix-co-2' /> +} +</programlisting> + + <calloutlist> + <callout arearefs='qt-default-nix-co-1'> + <para> + Import Qt modules directly, that is: <literal>qtbase</literal>, <literal>qtdeclarative</literal>, etc. + <emphasis>Do not</emphasis> import Qt package sets such as <literal>qt5</literal> + because the Qt versions of dependencies may not be coherent, causing build and runtime failures. + </para> + </callout> + <callout arearefs='qt-default-nix-co-2'> + <para> + All Qt packages must include <literal>wrapQtAppsHook</literal> in + <literal>nativeBuildInputs</literal>, or you must explicitly set + <literal>dontWrapQtApps</literal>. + </para> + </callout> + </calloutlist> +``` + +## Locating runtime dependencies {#qt-runtime-dependencies} + +Qt applications must be wrapped to find runtime dependencies. +Include `wrapQtAppsHook` in `nativeBuildInputs`: + +```nix +{ stdenv, wrapQtAppsHook }: + +stdenv.mkDerivation { + # ... + nativeBuildInputs = [ wrapQtAppsHook ]; +} +``` + +Add entries to `qtWrapperArgs` are to modify the wrappers created by +`wrapQtAppsHook`: + +```nix +{ stdenv, wrapQtAppsHook }: + +stdenv.mkDerivation { + # ... + nativeBuildInputs = [ wrapQtAppsHook ]; + qtWrapperArgs = [ ''--prefix PATH : /path/to/bin'' ]; +} +``` + +The entries are passed as arguments to [wrapProgram](#fun-wrapProgram). + +Set `dontWrapQtApps` to stop applications from being wrapped automatically. +Wrap programs manually with `wrapQtApp`, using the syntax of +[wrapProgram](#fun-wrapProgram): + +```nix +{ stdenv, lib, wrapQtAppsHook }: + +stdenv.mkDerivation { + # ... + nativeBuildInputs = [ wrapQtAppsHook ]; + dontWrapQtApps = true; + preFixup = '' + wrapQtApp "$out/bin/myapp" --prefix PATH : /path/to/bin + ''; +} +``` + +::: {.note} +`wrapQtAppsHook` ignores files that are non-ELF executables. +This means that scripts won't be automatically wrapped so you'll need to manually wrap them as previously mentioned. +An example of when you'd always need to do this is with Python applications that use PyQt. +::: + +## Adding a library to Nixpkgs {#adding-a-library-to-nixpkgs} + +Add Qt libraries to `qt5-packages.nix` to make them available for every +supported Qt version. + +### Example adding a Qt library {#qt-library-all-packages-nix} + +The following represents the contents of `qt5-packages.nix`. + +```nix +{ + # ... + + mylib = callPackage ../path/to/mylib {}; + + # ... +} +``` + +Libraries are built with every available version of Qt. +Use the `meta.broken` attribute to disable the package for unsupported Qt versions: + +```nix +{ stdenv, lib, qtbase }: + +stdenv.mkDerivation { + # ... + # Disable this library with Qt < 5.9.0 + meta.broken = lib.versionOlder qtbase.version "5.9.0"; +} +``` + +## Adding an application to Nixpkgs {#adding-an-application-to-nixpkgs} + +Add Qt applications to `qt5-packages.nix`. Add an alias to `all-packages.nix` +to select the Qt 5 version used for the application. + +### Example adding a Qt application {#qt-application-all-packages-nix} + +The following represents the contents of `qt5-packages.nix`. + +```nix +{ + # ... + + myapp = callPackage ../path/to/myapp {}; + + # ... +} +``` + +The following represents the contents of `all-packages.nix`. + +```nix +{ + # ... + + myapp = libsForQt5.myapp; + + # ... +} +``` diff --git a/doc/languages-frameworks/r.section.md b/doc/languages-frameworks/r.section.md new file mode 100644 index 00000000000..ad0fb10987c --- /dev/null +++ b/doc/languages-frameworks/r.section.md @@ -0,0 +1,127 @@ +# R {#r} + +## Installation {#installation} + +Define an environment for R that contains all the libraries that you'd like to +use by adding the following snippet to your $HOME/.config/nixpkgs/config.nix file: + +```nix +{ + packageOverrides = super: let self = super.pkgs; in + { + + rEnv = super.rWrapper.override { + packages = with self.rPackages; [ + devtools + ggplot2 + reshape2 + yaml + optparse + ]; + }; + }; +} +``` + +Then you can use `nix-env -f "<nixpkgs>" -iA rEnv` to install it into your user +profile. The set of available libraries can be discovered by running the +command `nix-env -f "<nixpkgs>" -qaP -A rPackages`. The first column from that +output is the name that has to be passed to rWrapper in the code snipped above. + +However, if you'd like to add a file to your project source to make the +environment available for other contributors, you can create a `default.nix` +file like so: + +```nix +with import <nixpkgs> {}; +{ + myProject = stdenv.mkDerivation { + name = "myProject"; + version = "1"; + src = if lib.inNixShell then null else nix; + + buildInputs = with rPackages; [ + R + ggplot2 + knitr + ]; + }; +} +``` +and then run `nix-shell .` to be dropped into a shell with those packages +available. + +## RStudio {#rstudio} + +RStudio uses a standard set of packages and ignores any custom R +environments or installed packages you may have. To create a custom +environment, see `rstudioWrapper`, which functions similarly to +`rWrapper`: + +```nix +{ + packageOverrides = super: let self = super.pkgs; in + { + + rstudioEnv = super.rstudioWrapper.override { + packages = with self.rPackages; [ + dplyr + ggplot2 + reshape2 + ]; + }; + }; +} +``` + +Then like above, `nix-env -f "<nixpkgs>" -iA rstudioEnv` will install +this into your user profile. + +Alternatively, you can create a self-contained `shell.nix` without the need to +modify any configuration files: + +```nix +{ pkgs ? import <nixpkgs> {} +}: + +pkgs.rstudioWrapper.override { + packages = with pkgs.rPackages; [ dplyr ggplot2 reshape2 ]; +} + +``` + +Executing `nix-shell` will then drop you into an environment equivalent to the +one above. If you need additional packages just add them to the list and +re-enter the shell. + +## Updating the package set {#updating-the-package-set} + +There is a script and associated environment for regenerating the package +sets and synchronising the rPackages tree to the current CRAN and matching +BIOC release. These scripts are found in the `pkgs/development/r-modules` +directory and executed as follows: + +```bash +nix-shell generate-shell.nix + +Rscript generate-r-packages.R cran > cran-packages.nix.new +mv cran-packages.nix.new cran-packages.nix + +Rscript generate-r-packages.R bioc > bioc-packages.nix.new +mv bioc-packages.nix.new bioc-packages.nix + +Rscript generate-r-packages.R bioc-annotation > bioc-annotation-packages.nix.new +mv bioc-annotation-packages.nix.new bioc-annotation-packages.nix + +Rscript generate-r-packages.R bioc-experiment > bioc-experiment-packages.nix.new +mv bioc-experiment-packages.nix.new bioc-experiment-packages.nix +``` + +`generate-r-packages.R <repo>` reads `<repo>-packages.nix`, therefore +the renaming. + +Some packages require overrides to specify external dependencies or other +patches and special requirements. These overrides are specified in the +`pkgs/development/r-modules/default.nix` file. As the `*-packages.nix` +contents are automatically generated it should not be edited and broken +builds should be addressed using overrides. diff --git a/doc/languages-frameworks/ruby.section.md b/doc/languages-frameworks/ruby.section.md new file mode 100644 index 00000000000..e29f97c566c --- /dev/null +++ b/doc/languages-frameworks/ruby.section.md @@ -0,0 +1,283 @@ +# Ruby {#sec-language-ruby} + +## Using Ruby {#using-ruby} + +Several versions of Ruby interpreters are available on Nix, as well as over 250 gems and many applications written in Ruby. The attribute `ruby` refers to the default Ruby interpreter, which is currently MRI 2.6. It's also possible to refer to specific versions, e.g. `ruby_2_y`, `jruby`, or `mruby`. + +In the Nixpkgs tree, Ruby packages can be found throughout, depending on what they do, and are called from the main package set. Ruby gems, however are separate sets, and there's one default set for each interpreter (currently MRI only). + +There are two main approaches for using Ruby with gems. One is to use a specifically locked `Gemfile` for an application that has very strict dependencies. The other is to depend on the common gems, which we'll explain further down, and rely on them being updated regularly. + +The interpreters have common attributes, namely `gems`, and `withPackages`. So you can refer to `ruby.gems.nokogiri`, or `ruby_2_7.gems.nokogiri` to get the Nokogiri gem already compiled and ready to use. + +Since not all gems have executables like `nokogiri`, it's usually more convenient to use the `withPackages` function like this: `ruby.withPackages (p: with p; [ nokogiri ])`. This will also make sure that the Ruby in your environment will be able to find the gem and it can be used in your Ruby code (for example via `ruby` or `irb` executables) via `require "nokogiri"` as usual. + +### Temporary Ruby environment with `nix-shell` {#temporary-ruby-environment-with-nix-shell} + +Rather than having a single Ruby environment shared by all Ruby development projects on a system, Nix allows you to create separate environments per project. `nix-shell` gives you the possibility to temporarily load another environment akin to a combined `chruby` or `rvm` and `bundle exec`. + +There are two methods for loading a shell with Ruby packages. The first and recommended method is to create an environment with `ruby.withPackages` and load that. + +```ShellSession +$ nix-shell -p "ruby.withPackages (ps: with ps; [ nokogiri pry ])" +``` + +The other method, which is not recommended, is to create an environment and list all the packages directly. + +```ShellSession +$ nix-shell -p ruby.gems.nokogiri ruby.gems.pry +``` + +Again, it's possible to launch the interpreter from the shell. The Ruby interpreter has the attribute `gems` which contains all Ruby gems for that specific interpreter. + +#### Load Ruby environment from `.nix` expression {#load-ruby-environment-from-.nix-expression} + +As explained in the Nix manual, `nix-shell` can also load an expression from a `.nix` file. Say we want to have Ruby 2.6, `nokogori`, and `pry`. Consider a `shell.nix` file with: + +```nix +with import <nixpkgs> {}; +ruby.withPackages (ps: with ps; [ nokogiri pry ]) +``` + +What's happening here? + +1. We begin with importing the Nix Packages collections. `import <nixpkgs>` imports the `<nixpkgs>` function, `{}` calls it and the `with` statement brings all attributes of `nixpkgs` in the local scope. These attributes form the main package set. +2. Then we create a Ruby environment with the `withPackages` function. +3. The `withPackages` function expects us to provide a function as an argument that takes the set of all ruby gems and returns a list of packages to include in the environment. Here, we select the packages `nokogiri` and `pry` from the package set. + +#### Execute command with `--run` {#execute-command-with---run} + +A convenient flag for `nix-shell` is `--run`. It executes a command in the `nix-shell`. We can e.g. directly open a `pry` REPL: + +```ShellSession +$ nix-shell -p "ruby.withPackages (ps: with ps; [ nokogiri pry ])" --run "pry" +``` + +Or immediately require `nokogiri` in pry: + +```ShellSession +$ nix-shell -p "ruby.withPackages (ps: with ps; [ nokogiri pry ])" --run "pry -rnokogiri" +``` + +Or run a script using this environment: + +```ShellSession +$ nix-shell -p "ruby.withPackages (ps: with ps; [ nokogiri pry ])" --run "ruby example.rb" +``` + +#### Using `nix-shell` as shebang {#using-nix-shell-as-shebang} + +In fact, for the last case, there is a more convenient method. You can add a [shebang](<https://en.wikipedia.org/wiki/Shebang_(Unix)>) to your script specifying which dependencies `nix-shell` needs. With the following shebang, you can just execute `./example.rb`, and it will run with all dependencies. + +```ruby +#! /usr/bin/env nix-shell +#! nix-shell -i ruby -p "ruby.withPackages (ps: with ps; [ nokogiri rest-client ])" + +require 'nokogiri' +require 'rest-client' + +body = RestClient.get('http://example.com').body +puts Nokogiri::HTML(body).at('h1').text +``` + +## Developing with Ruby {#developing-with-ruby} + +### Using an existing Gemfile {#using-an-existing-gemfile} + +In most cases, you'll already have a `Gemfile.lock` listing all your dependencies. This can be used to generate a `gemset.nix` which is used to fetch the gems and combine them into a single environment. The reason why you need to have a separate file for this, is that Nix requires you to have a checksum for each input to your build. Since the `Gemfile.lock` that `bundler` generates doesn't provide us with checksums, we have to first download each gem, calculate its SHA256, and store it in this separate file. + +So the steps from having just a `Gemfile` to a `gemset.nix` are: + +```ShellSession +$ bundle lock +$ bundix +``` + +If you already have a `Gemfile.lock`, you can simply run `bundix` and it will work the same. + +To update the gems in your `Gemfile.lock`, you may use the `bundix -l` flag, which will create a new `Gemfile.lock` in case the `Gemfile` has a more recent time of modification. + +Once the `gemset.nix` is generated, it can be used in a `bundlerEnv` derivation. Here is an example you could use for your `shell.nix`: + +```nix +# ... +let + gems = bundlerEnv { + name = "gems-for-some-project"; + gemdir = ./.; + }; +in mkShell { packages = [ gems gems.wrappedRuby ]; } +``` + +With this file in your directory, you can run `nix-shell` to build and use the gems. The important parts here are `bundlerEnv` and `wrappedRuby`. + +The `bundlerEnv` is a wrapper over all the gems in your gemset. This means that all the `/lib` and `/bin` directories will be available, and the executables of all gems (even of indirect dependencies) will end up in your `$PATH`. The `wrappedRuby` provides you with all executables that come with Ruby itself, but wrapped so they can easily find the gems in your gemset. + +One common issue that you might have is that you have Ruby 2.6, but also `bundler` in your gemset. That leads to a conflict for `/bin/bundle` and `/bin/bundler`. You can resolve this by wrapping either your Ruby or your gems in a `lowPrio` call. So in order to give the `bundler` from your gemset priority, it would be used like this: + +```nix +# ... +mkShell { buildInputs = [ gems (lowPrio gems.wrappedRuby) ]; } +``` + +### Gem-specific configurations and workarounds {#gem-specific-configurations-and-workarounds} + +In some cases, especially if the gem has native extensions, you might need to modify the way the gem is built. + +This is done via a common configuration file that includes all of the workarounds for each gem. + +This file lives at `/pkgs/development/ruby-modules/gem-config/default.nix`, since it already contains a lot of entries, it should be pretty easy to add the modifications you need for your needs. + +In the meanwhile, or if the modification is for a private gem, you can also add the configuration to only your own environment. + +Two places that allow this modification are the `ruby` derivation, or `bundlerEnv`. + +Here's the `ruby` one: + +```nix +{ pg_version ? "10", pkgs ? import <nixpkgs> { } }: +let + myRuby = pkgs.ruby.override { + defaultGemConfig = pkgs.defaultGemConfig // { + pg = attrs: { + buildFlags = + [ "--with-pg-config=${pkgs."postgresql_${pg_version}"}/bin/pg_config" ]; + }; + }; + }; +in myRuby.withPackages (ps: with ps; [ pg ]) +``` + +And an example with `bundlerEnv`: + +```nix +{ pg_version ? "10", pkgs ? import <nixpkgs> { } }: +let + gems = pkgs.bundlerEnv { + name = "gems-for-some-project"; + gemdir = ./.; + gemConfig = pkgs.defaultGemConfig // { + pg = attrs: { + buildFlags = + [ "--with-pg-config=${pkgs."postgresql_${pg_version}"}/bin/pg_config" ]; + }; + }; + }; +in mkShell { buildInputs = [ gems gems.wrappedRuby ]; } +``` + +And finally via overlays: + +```nix +{ pg_version ? "10" }: +let + pkgs = import <nixpkgs> { + overlays = [ + (self: super: { + defaultGemConfig = super.defaultGemConfig // { + pg = attrs: { + buildFlags = [ + "--with-pg-config=${ + pkgs."postgresql_${pg_version}" + }/bin/pg_config" + ]; + }; + }; + }) + ]; + }; +in pkgs.ruby.withPackages (ps: with ps; [ pg ]) +``` + +Then we can get whichever postgresql version we desire and the `pg` gem will always reference it correctly: + +```ShellSession +$ nix-shell --argstr pg_version 9_4 --run 'ruby -rpg -e "puts PG.library_version"' +90421 + +$ nix-shell --run 'ruby -rpg -e "puts PG.library_version"' +100007 +``` + +Of course for this use-case one could also use overlays since the configuration for `pg` depends on the `postgresql` alias, but for demonstration purposes this has to suffice. + +### Platform-specific gems + +Right now, bundix has some issues with pre-built, platform-specific gems: [bundix PR #68](https://github.com/nix-community/bundix/pull/68). +Until this is solved, you can tell bundler to not use platform-specific gems and instead build them from source each time: +- globally (will be set in `~/.config/.bundle/config`): +```shell +$ bundle config set force_ruby_platform true +``` +- locally (will be set in `<project-root>/.bundle/config`): +```shell +$ bundle config set --local force_ruby_platform true +``` + +### Adding a gem to the default gemset {#adding-a-gem-to-the-default-gemset} + +Now that you know how to get a working Ruby environment with Nix, it's time to go forward and start actually developing with Ruby. We will first have a look at how Ruby gems are packaged on Nix. Then, we will look at how you can use development mode with your code. + +All gems in the standard set are automatically generated from a single `Gemfile`. The dependency resolution is done with `bundler` and makes it more likely that all gems are compatible to each other. + +In order to add a new gem to nixpkgs, you can put it into the `/pkgs/development/ruby-modules/with-packages/Gemfile` and run `./maintainers/scripts/update-ruby-packages`. + +To test that it works, you can then try using the gem with: + +```shell +NIX_PATH=nixpkgs=$PWD nix-shell -p "ruby.withPackages (ps: with ps; [ name-of-your-gem ])" +``` + +### Packaging applications {#packaging-applications} + +A common task is to add a ruby executable to nixpkgs, popular examples would be `chef`, `jekyll`, or `sass`. A good way to do that is to use the `bundlerApp` function, that allows you to make a package that only exposes the listed executables, otherwise the package may cause conflicts through common paths like `bin/rake` or `bin/bundler` that aren't meant to be used. + +The absolute easiest way to do that is to write a `Gemfile` along these lines: + +```ruby +source 'https://rubygems.org' do + gem 'mdl' +end +``` + +If you want to package a specific version, you can use the standard Gemfile syntax for that, e.g. `gem 'mdl', '0.5.0'`, but if you want the latest stable version anyway, it's easier to update by simply running the `bundle lock` and `bundix` steps again. + +Now you can also make a `default.nix` that looks like this: + +```nix +{ bundlerApp }: + +bundlerApp { + pname = "mdl"; + gemdir = ./.; + exes = [ "mdl" ]; +} +``` + +All that's left to do is to generate the corresponding `Gemfile.lock` and `gemset.nix` as described above in the `Using an existing Gemfile` section. + +#### Packaging executables that require wrapping {#packaging-executables-that-require-wrapping} + +Sometimes your app will depend on other executables at runtime, and tries to find it through the `PATH` environment variable. + +In this case, you can provide a `postBuild` hook to `bundlerApp` that wraps the gem in another script that prefixes the `PATH`. + +Of course you could also make a custom `gemConfig` if you know exactly how to patch it, but it's usually much easier to maintain with a simple wrapper so the patch doesn't have to be adjusted for each version. + +Here's another example: + +```nix +{ lib, bundlerApp, makeWrapper, git, gnutar, gzip }: + +bundlerApp { + pname = "r10k"; + gemdir = ./.; + exes = [ "r10k" ]; + + buildInputs = [ makeWrapper ]; + + postBuild = '' + wrapProgram $out/bin/r10k --prefix PATH : ${lib.makeBinPath [ git gnutar gzip ]} + ''; +} +``` diff --git a/doc/languages-frameworks/rust.section.md b/doc/languages-frameworks/rust.section.md new file mode 100644 index 00000000000..e19783e29e6 --- /dev/null +++ b/doc/languages-frameworks/rust.section.md @@ -0,0 +1,1008 @@ +# Rust {#rust} + +To install the rust compiler and cargo put + +```nix +environment.systemPackages = [ + rustc + cargo +]; +``` + +into your `configuration.nix` or bring them into scope with `nix-shell -p rustc cargo`. + +For other versions such as daily builds (beta and nightly), +use either `rustup` from nixpkgs (which will manage the rust installation in your home directory), +or use a community maintained [Rust overlay](#using-community-rust-overlays). + +## Compiling Rust applications with Cargo {#compiling-rust-applications-with-cargo} + +Rust applications are packaged by using the `buildRustPackage` helper from `rustPlatform`: + +```nix +{ lib, fetchFromGitHub, rustPlatform }: + +rustPlatform.buildRustPackage rec { + pname = "ripgrep"; + version = "12.1.1"; + + src = fetchFromGitHub { + owner = "BurntSushi"; + repo = pname; + rev = version; + sha256 = "1hqps7l5qrjh9f914r5i6kmcz6f1yb951nv4lby0cjnp5l253kps"; + }; + + cargoSha256 = "03wf9r2csi6jpa7v5sw5lpxkrk4wfzwmzx7k3991q3bdjzcwnnwp"; + + meta = with lib; { + description = "A fast line-oriented regex search tool, similar to ag and ack"; + homepage = "https://github.com/BurntSushi/ripgrep"; + license = licenses.unlicense; + maintainers = [ maintainers.tailhook ]; + }; +} +``` + +`buildRustPackage` requires either the `cargoSha256` or the +`cargoHash` attribute which is computed over all crate sources of this +package. `cargoHash256` is used for traditional Nix SHA-256 hashes, +such as the one in the example above. `cargoHash` should instead be +used for [SRI](https://www.w3.org/TR/SRI/) hashes. For example: + +```nix + cargoHash = "sha256-l1vL2ZdtDRxSGvP0X/l3nMw8+6WF67KPutJEzUROjg8="; +``` + +Both types of hashes are permitted when contributing to nixpkgs. The +Cargo hash is obtained by inserting a fake checksum into the +expression and building the package once. The correct checksum can +then be taken from the failed build. A fake hash can be used for +`cargoSha256` as follows: + +```nix + cargoSha256 = lib.fakeSha256; +``` + +For `cargoHash` you can use: + +```nix + cargoHash = lib.fakeHash; +``` + +Per the instructions in the [Cargo Book](https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html) +best practices guide, Rust applications should always commit the `Cargo.lock` +file in git to ensure a reproducible build. However, a few packages do not, and +Nix depends on this file, so if it is missing you can use `cargoPatches` to +apply it in the `patchPhase`. Consider sending a PR upstream with a note to the +maintainer describing why it's important to include in the application. + +The fetcher will verify that the `Cargo.lock` file is in sync with the `src` +attribute, and fail the build if not. It will also will compress the vendor +directory into a tar.gz archive. + +The tarball with vendored dependencies contains a directory with the +package's `name`, which is normally composed of `pname` and +`version`. This means that the vendored dependencies hash +(`cargoSha256`/`cargoHash`) is dependent on the package name and +version. The `cargoDepsName` attribute can be used to use another name +for the directory of vendored dependencies. For example, the hash can +be made invariant to the version by setting `cargoDepsName` to +`pname`: + +```nix +rustPlatform.buildRustPackage rec { + pname = "broot"; + version = "1.2.0"; + + src = fetchCrate { + inherit pname version; + sha256 = "1mqaynrqaas82f5957lx31x80v74zwmwmjxxlbywajb61vh00d38"; + }; + + cargoHash = "sha256-JmBZcDVYJaK1cK05cxx5BrnGWp4t8ca6FLUbvIot67s="; + cargoDepsName = pname; + + # ... +} +``` + +### Importing a `Cargo.lock` file {#importing-a-cargo.lock-file} + +Using `cargoSha256` or `cargoHash` is tedious when using +`buildRustPackage` within a project, since it requires that the hash +is updated after every change to `Cargo.lock`. Therefore, +`buildRustPackage` also supports vendoring dependencies directly from +a `Cargo.lock` file using the `cargoLock` argument. For example: + +```nix +rustPlatform.buildRustPackage { + pname = "myproject"; + version = "1.0.0"; + + cargoLock = { + lockFile = ./Cargo.lock; + }; + + # ... +} +``` + +This will retrieve the dependencies using fixed-output derivations from +the specified lockfile. + +One caveat is that `Cargo.lock` cannot be patched in the `patchPhase` +because it runs after the dependencies have already been fetched. If +you need to patch or generate the lockfile you can alternatively set +`cargoLock.lockFileContents` to a string of its contents: + +```nix +rustPlatform.buildRustPackage { + pname = "myproject"; + version = "1.0.0"; + + cargoLock = let + fixupLockFile = path: f (builtins.readFile path); + in { + lockFileContents = fixupLockFile ./Cargo.lock; + }; + + # ... +} +``` + +Note that setting `cargoLock.lockFile` or `cargoLock.lockFileContents` +doesn't add a `Cargo.lock` to your `src`, and a `Cargo.lock` is still +required to build a rust package. A simple fix is to use: + +```nix +postPatch = '' + cp ${./Cargo.lock} Cargo.lock +''; +``` + +The output hash of each dependency that uses a git source must be +specified in the `outputHashes` attribute. For example: + +```nix +rustPlatform.buildRustPackage rec { + pname = "myproject"; + version = "1.0.0"; + + cargoLock = { + lockFile = ./Cargo.lock; + outputHashes = { + "finalfusion-0.14.0" = "17f4bsdzpcshwh74w5z119xjy2if6l2wgyjy56v621skr2r8y904"; + }; + }; + + # ... +} +``` + +If you do not specify an output hash for a git dependency, building +the package will fail and inform you of which crate needs to be +added. To find the correct hash, you can first use `lib.fakeSha256` or +`lib.fakeHash` as a stub hash. Building the package (and thus the +vendored dependencies) will then inform you of the correct hash. + +### Cargo features {#cargo-features} + +You can disable default features using `buildNoDefaultFeatures`, and +extra features can be added with `buildFeatures`. + +If you want to use different features for check phase, you can use +`checkNoDefaultFeatures` and `checkFeatures`. They are only passed to +`cargo test` and not `cargo build`. If left unset, they default to +`buildNoDefaultFeatures` and `buildFeatures`. + +For example: + +```nix +rustPlatform.buildRustPackage rec { + pname = "myproject"; + version = "1.0.0"; + + buildNoDefaultFeatures = true; + buildFeatures = [ "color" "net" ]; + + # disable network features in tests + checkFeatures = [ "color" ]; + + # ... +} +``` + +### Cross compilation {#cross-compilation} + +By default, Rust packages are compiled for the host platform, just like any +other package is. The `--target` passed to rust tools is computed from this. +By default, it takes the `stdenv.hostPlatform.config` and replaces components +where they are known to differ. But there are ways to customize the argument: + + - To choose a different target by name, define + `stdenv.hostPlatform.rustc.config` as that name (a string), and that + name will be used instead. + + For example: + + ```nix + import <nixpkgs> { + crossSystem = (import <nixpkgs/lib>).systems.examples.armhf-embedded // { + rustc.config = "thumbv7em-none-eabi"; + }; + } + ``` + + will result in: + + ```shell + --target thumbv7em-none-eabi + ``` + + - To pass a completely custom target, define + `stdenv.hostPlatform.rustc.config` with its name, and + `stdenv.hostPlatform.rustc.platform` with the value. The value will be + serialized to JSON in a file called + `${stdenv.hostPlatform.rustc.config}.json`, and the path of that file + will be used instead. + + For example: + + ```nix + import <nixpkgs> { + crossSystem = (import <nixpkgs/lib>).systems.examples.armhf-embedded // { + rustc.config = "thumb-crazy"; + rustc.platform = { foo = ""; bar = ""; }; + }; + } + ``` + + will result in: + + ```shell + --target /nix/store/asdfasdfsadf-thumb-crazy.json # contains {"foo":"","bar":""} + ``` + +Note that currently custom targets aren't compiled with `std`, so `cargo test` +will fail. This can be ignored by adding `doCheck = false;` to your derivation. + +### Running package tests {#running-package-tests} + +When using `buildRustPackage`, the `checkPhase` is enabled by default and runs +`cargo test` on the package to build. To make sure that we don't compile the +sources twice and to actually test the artifacts that will be used at runtime, +the tests will be ran in the `release` mode by default. + +However, in some cases the test-suite of a package doesn't work properly in the +`release` mode. For these situations, the mode for `checkPhase` can be changed like +so: + +```nix +rustPlatform.buildRustPackage { + /* ... */ + checkType = "debug"; +} +``` + +Please note that the code will be compiled twice here: once in `release` mode +for the `buildPhase`, and again in `debug` mode for the `checkPhase`. + +Test flags, e.g., `--package foo`, can be passed to `cargo test` via the +`cargoTestFlags` attribute. + +Another attribute, called `checkFlags`, is used to pass arguments to the test +binary itself, as stated +[here](https://doc.rust-lang.org/cargo/commands/cargo-test.html). + +#### Tests relying on the structure of the `target/` directory {#tests-relying-on-the-structure-of-the-target-directory} + +Some tests may rely on the structure of the `target/` directory. Those tests +are likely to fail because we use `cargo --target` during the build. This means that +the artifacts +[are stored in `target/<architecture>/release/`](https://doc.rust-lang.org/cargo/guide/build-cache.html), +rather than in `target/release/`. + +This can only be worked around by patching the affected tests accordingly. + +#### Disabling package-tests {#disabling-package-tests} + +In some instances, it may be necessary to disable testing altogether (with `doCheck = false;`): + +* If no tests exist -- the `checkPhase` should be explicitly disabled to skip + unnecessary build steps to speed up the build. +* If tests are highly impure (e.g. due to network usage). + +There will obviously be some corner-cases not listed above where it's sensible to disable tests. +The above are just guidelines, and exceptions may be granted on a case-by-case basis. + +However, please check if it's possible to disable a problematic subset of the +test suite and leave a comment explaining your reasoning. + +#### Setting `test-threads` {#setting-test-threads} + +`buildRustPackage` will use parallel test threads by default, +sometimes it may be necessary to disable this so the tests run consecutively. + +```nix +rustPlatform.buildRustPackage { + /* ... */ + dontUseCargoParallelTests = true; +} +``` + +### Building a package in `debug` mode {#building-a-package-in-debug-mode} + +By default, `buildRustPackage` will use `release` mode for builds. If a package +should be built in `debug` mode, it can be configured like so: + +```nix +rustPlatform.buildRustPackage { + /* ... */ + buildType = "debug"; +} +``` + +In this scenario, the `checkPhase` will be ran in `debug` mode as well. + +### Custom `build`/`install`-procedures {#custom-buildinstall-procedures} + +Some packages may use custom scripts for building/installing, e.g. with a `Makefile`. +In these cases, it's recommended to override the `buildPhase`/`installPhase`/`checkPhase`. + +Otherwise, some steps may fail because of the modified directory structure of `target/`. + +### Building a crate with an absent or out-of-date Cargo.lock file {#building-a-crate-with-an-absent-or-out-of-date-cargo.lock-file} + +`buildRustPackage` needs a `Cargo.lock` file to get all dependencies in the +source code in a reproducible way. If it is missing or out-of-date one can use +the `cargoPatches` attribute to update or add it. + +```nix +rustPlatform.buildRustPackage rec { + (...) + cargoPatches = [ + # a patch file to add/update Cargo.lock in the source code + ./add-Cargo.lock.patch + ]; +} +``` + +## Compiling non-Rust packages that include Rust code {#compiling-non-rust-packages-that-include-rust-code} + +Several non-Rust packages incorporate Rust code for performance- or +security-sensitive parts. `rustPlatform` exposes several functions and +hooks that can be used to integrate Cargo in non-Rust packages. + +### Vendoring of dependencies {#vendoring-of-dependencies} + +Since network access is not allowed in sandboxed builds, Rust crate +dependencies need to be retrieved using a fetcher. `rustPlatform` +provides the `fetchCargoTarball` fetcher, which vendors all +dependencies of a crate. For example, given a source path `src` +containing `Cargo.toml` and `Cargo.lock`, `fetchCargoTarball` +can be used as follows: + +```nix +cargoDeps = rustPlatform.fetchCargoTarball { + inherit src; + hash = "sha256-BoHIN/519Top1NUBjpB/oEMqi86Omt3zTQcXFWqrek0="; +}; +``` + +The `src` attribute is required, as well as a hash specified through +one of the `sha256` or `hash` attributes. The following optional +attributes can also be used: + +* `name`: the name that is used for the dependencies tarball. If + `name` is not specified, then the name `cargo-deps` will be used. +* `sourceRoot`: when the `Cargo.lock`/`Cargo.toml` are in a + subdirectory, `sourceRoot` specifies the relative path to these + files. +* `patches`: patches to apply before vendoring. This is useful when + the `Cargo.lock`/`Cargo.toml` files need to be patched before + vendoring. + +If a `Cargo.lock` file is available, you can alternatively use the +`importCargoLock` function. In contrast to `fetchCargoTarball`, this +function does not require a hash (unless git dependencies are used) +and fetches every dependency as a separate fixed-output derivation. +`importCargoLock` can be used as follows: + +``` +cargoDeps = rustPlatform.importCargoLock { + lockFile = ./Cargo.lock; +}; +``` + +If the `Cargo.lock` file includes git dependencies, then their output +hashes need to be specified since they are not available through the +lock file. For example: + +``` +cargoDeps = rustPlatform.importCargoLock { + lockFile = ./Cargo.lock; + outputHashes = { + "rand-0.8.3" = "0ya2hia3cn31qa8894s3av2s8j5bjwb6yq92k0jsnlx7jid0jwqa"; + }; +}; +``` + +If you do not specify an output hash for a git dependency, building +`cargoDeps` will fail and inform you of which crate needs to be +added. To find the correct hash, you can first use `lib.fakeSha256` or +`lib.fakeHash` as a stub hash. Building `cargoDeps` will then inform +you of the correct hash. + +### Hooks {#hooks} + +`rustPlatform` provides the following hooks to automate Cargo builds: + +* `cargoSetupHook`: configure Cargo to use dependencies vendored + through `fetchCargoTarball`. This hook uses the `cargoDeps` + environment variable to find the vendored dependencies. If a project + already vendors its dependencies, the variable `cargoVendorDir` can + be used instead. When the `Cargo.toml`/`Cargo.lock` files are not in + `sourceRoot`, then the optional `cargoRoot` is used to specify the + Cargo root directory relative to `sourceRoot`. +* `cargoBuildHook`: use Cargo to build a crate. If the crate to be + built is a crate in e.g. a Cargo workspace, the relative path to the + crate to build can be set through the optional `buildAndTestSubdir` + environment variable. Features can be specified with + `cargoBuildNoDefaultFeatures` and `cargoBuildFeatures`. Additional + Cargo build flags can be passed through `cargoBuildFlags`. +* `maturinBuildHook`: use [Maturin](https://github.com/PyO3/maturin) + to build a Python wheel. Similar to `cargoBuildHook`, the optional + variable `buildAndTestSubdir` can be used to build a crate in a + Cargo workspace. Additional Maturin flags can be passed through + `maturinBuildFlags`. +* `cargoCheckHook`: run tests using Cargo. The build type for checks + can be set using `cargoCheckType`. Features can be specified with + `cargoCheckNoDefaultFeaatures` and `cargoCheckFeatures`. Additional + flags can be passed to the tests using `checkFlags` and + `checkFlagsArray`. By default, tests are run in parallel. This can + be disabled by setting `dontUseCargoParallelTests`. +* `cargoInstallHook`: install binaries and static/shared libraries + that were built using `cargoBuildHook`. +* `bindgenHook`: for crates which use `bindgen` as a build dependency, lets + `bindgen` find `libclang` and `libclang` find the libraries in `buildInputs`. + +### Examples {#examples} + +#### Python package using `setuptools-rust` {#python-package-using-setuptools-rust} + +For Python packages using `setuptools-rust`, you can use +`fetchCargoTarball` and `cargoSetupHook` to retrieve and set up Cargo +dependencies. The build itself is then performed by +`buildPythonPackage`. + +The following example outlines how the `tokenizers` Python package is +built. Since the Python package is in the `source/bindings/python` +directory of the `tokenizers` project's source archive, we use +`sourceRoot` to point the tooling to this directory: + +```nix +{ fetchFromGitHub +, buildPythonPackage +, rustPlatform +, setuptools-rust +}: + +buildPythonPackage rec { + pname = "tokenizers"; + version = "0.10.0"; + + src = fetchFromGitHub { + owner = "huggingface"; + repo = pname; + rev = "python-v${version}"; + hash = "sha256-rQ2hRV52naEf6PvRsWVCTN7B1oXAQGmnpJw4iIdhamw="; + }; + + cargoDeps = rustPlatform.fetchCargoTarball { + inherit src sourceRoot; + name = "${pname}-${version}"; + hash = "sha256-BoHIN/519Top1NUBjpB/oEMqi86Omt3zTQcXFWqrek0="; + }; + + sourceRoot = "source/bindings/python"; + + nativeBuildInputs = [ setuptools-rust ] ++ (with rustPlatform; [ + cargoSetupHook + rust.cargo + rust.rustc + ]); + + # ... +} +``` + +In some projects, the Rust crate is not in the main Python source +directory. In such cases, the `cargoRoot` attribute can be used to +specify the crate's directory relative to `sourceRoot`. In the +following example, the crate is in `src/rust`, as specified in the +`cargoRoot` attribute. Note that we also need to specify the correct +path for `fetchCargoTarball`. + +```nix + +{ buildPythonPackage +, fetchPypi +, rustPlatform +, setuptools-rust +, openssl +}: + +buildPythonPackage rec { + pname = "cryptography"; + version = "3.4.2"; # Also update the hash in vectors.nix + + src = fetchPypi { + inherit pname version; + sha256 = "1i1mx5y9hkyfi9jrrkcw804hmkcglxi6rmf7vin7jfnbr2bf4q64"; + }; + + cargoDeps = rustPlatform.fetchCargoTarball { + inherit src; + sourceRoot = "${pname}-${version}/${cargoRoot}"; + name = "${pname}-${version}"; + hash = "sha256-PS562W4L1NimqDV2H0jl5vYhL08H9est/pbIxSdYVfo="; + }; + + cargoRoot = "src/rust"; + + # ... +} +``` + +#### Python package using `maturin` {#python-package-using-maturin} + +Python packages that use [Maturin](https://github.com/PyO3/maturin) +can be built with `fetchCargoTarball`, `cargoSetupHook`, and +`maturinBuildHook`. For example, the following (partial) derivation +builds the `retworkx` Python package. `fetchCargoTarball` and +`cargoSetupHook` are used to fetch and set up the crate dependencies. +`maturinBuildHook` is used to perform the build. + +```nix +{ lib +, buildPythonPackage +, rustPlatform +, fetchFromGitHub +}: + +buildPythonPackage rec { + pname = "retworkx"; + version = "0.6.0"; + + src = fetchFromGitHub { + owner = "Qiskit"; + repo = "retworkx"; + rev = version; + sha256 = "11n30ldg3y3y6qxg3hbj837pnbwjkqw3nxq6frds647mmmprrd20"; + }; + + cargoDeps = rustPlatform.fetchCargoTarball { + inherit src; + name = "${pname}-${version}"; + hash = "sha256-heOBK8qi2nuc/Ib+I/vLzZ1fUUD/G/KTw9d7M4Hz5O0="; + }; + + format = "pyproject"; + + nativeBuildInputs = with rustPlatform; [ cargoSetupHook maturinBuildHook ]; + + # ... +} +``` + +## Compiling Rust crates using Nix instead of Cargo {#compiling-rust-crates-using-nix-instead-of-cargo} + +### Simple operation {#simple-operation} + +When run, `cargo build` produces a file called `Cargo.lock`, +containing pinned versions of all dependencies. Nixpkgs contains a +tool called `carnix` (`nix-env -iA nixos.carnix`), which can be used +to turn a `Cargo.lock` into a Nix expression. + +That Nix expression calls `rustc` directly (hence bypassing Cargo), +and can be used to compile a crate and all its dependencies. Here is +an example for a minimal `hello` crate: + +```ShellSession +$ cargo new hello +$ cd hello +$ cargo build + Compiling hello v0.1.0 (file:///tmp/hello) + Finished dev [unoptimized + debuginfo] target(s) in 0.20 secs +$ carnix -o hello.nix --src ./. Cargo.lock --standalone +$ nix-build hello.nix -A hello_0_1_0 +``` + +Now, the file produced by the call to `carnix`, called `hello.nix`, looks like: + +```nix +# Generated by carnix 0.6.5: carnix -o hello.nix --src ./. Cargo.lock --standalone +{ stdenv, buildRustCrate, fetchgit }: +let kernel = stdenv.buildPlatform.parsed.kernel.name; + # ... (content skipped) +in +rec { + hello = f: hello_0_1_0 { features = hello_0_1_0_features { hello_0_1_0 = f; }; }; + hello_0_1_0_ = { dependencies?[], buildDependencies?[], features?[] }: buildRustCrate { + crateName = "hello"; + version = "0.1.0"; + authors = [ "pe@pijul.org <pe@pijul.org>" ]; + src = ./.; + inherit dependencies buildDependencies features; + }; + hello_0_1_0 = { features?(hello_0_1_0_features {}) }: hello_0_1_0_ {}; + hello_0_1_0_features = f: updateFeatures f (rec { + hello_0_1_0.default = (f.hello_0_1_0.default or true); + }) [ ]; +} +``` + +In particular, note that the argument given as `--src` is copied +verbatim to the source. If we look at a more complicated +dependencies, for instance by adding a single line `libc="*"` to our +`Cargo.toml`, we first need to run `cargo build` to update the +`Cargo.lock`. Then, `carnix` needs to be run again, and produces the +following nix file: + +```nix +# Generated by carnix 0.6.5: carnix -o hello.nix --src ./. Cargo.lock --standalone +{ stdenv, buildRustCrate, fetchgit }: +let kernel = stdenv.buildPlatform.parsed.kernel.name; + # ... (content skipped) +in +rec { + hello = f: hello_0_1_0 { features = hello_0_1_0_features { hello_0_1_0 = f; }; }; + hello_0_1_0_ = { dependencies?[], buildDependencies?[], features?[] }: buildRustCrate { + crateName = "hello"; + version = "0.1.0"; + authors = [ "pe@pijul.org <pe@pijul.org>" ]; + src = ./.; + inherit dependencies buildDependencies features; + }; + libc_0_2_36_ = { dependencies?[], buildDependencies?[], features?[] }: buildRustCrate { + crateName = "libc"; + version = "0.2.36"; + authors = [ "The Rust Project Developers" ]; + sha256 = "01633h4yfqm0s302fm0dlba469bx8y6cs4nqc8bqrmjqxfxn515l"; + inherit dependencies buildDependencies features; + }; + hello_0_1_0 = { features?(hello_0_1_0_features {}) }: hello_0_1_0_ { + dependencies = mapFeatures features ([ libc_0_2_36 ]); + }; + hello_0_1_0_features = f: updateFeatures f (rec { + hello_0_1_0.default = (f.hello_0_1_0.default or true); + libc_0_2_36.default = true; + }) [ libc_0_2_36_features ]; + libc_0_2_36 = { features?(libc_0_2_36_features {}) }: libc_0_2_36_ { + features = mkFeatures (features.libc_0_2_36 or {}); + }; + libc_0_2_36_features = f: updateFeatures f (rec { + libc_0_2_36.default = (f.libc_0_2_36.default or true); + libc_0_2_36.use_std = + (f.libc_0_2_36.use_std or false) || + (f.libc_0_2_36.default or false) || + (libc_0_2_36.default or false); + }) []; +} +``` + +Here, the `libc` crate has no `src` attribute, so `buildRustCrate` +will fetch it from [crates.io](https://crates.io). A `sha256` +attribute is still needed for Nix purity. + +### Handling external dependencies {#handling-external-dependencies} + +Some crates require external libraries. For crates from +[crates.io](https://crates.io), such libraries can be specified in +`defaultCrateOverrides` package in nixpkgs itself. + +Starting from that file, one can add more overrides, to add features +or build inputs by overriding the hello crate in a separate file. + +```nix +with import <nixpkgs> {}; +((import ./hello.nix).hello {}).override { + crateOverrides = defaultCrateOverrides // { + hello = attrs: { buildInputs = [ openssl ]; }; + }; +} +``` + +Here, `crateOverrides` is expected to be a attribute set, where the +key is the crate name without version number and the value a function. +The function gets all attributes passed to `buildRustCrate` as first +argument and returns a set that contains all attribute that should be +overwritten. + +For more complicated cases, such as when parts of the crate's +derivation depend on the crate's version, the `attrs` argument of +the override above can be read, as in the following example, which +patches the derivation: + +```nix +with import <nixpkgs> {}; +((import ./hello.nix).hello {}).override { + crateOverrides = defaultCrateOverrides // { + hello = attrs: lib.optionalAttrs (lib.versionAtLeast attrs.version "1.0") { + postPatch = '' + substituteInPlace lib/zoneinfo.rs \ + --replace "/usr/share/zoneinfo" "${tzdata}/share/zoneinfo" + ''; + }; + }; +} +``` + +Another situation is when we want to override a nested +dependency. This actually works in the exact same way, since the +`crateOverrides` parameter is forwarded to the crate's +dependencies. For instance, to override the build inputs for crate +`libc` in the example above, where `libc` is a dependency of the main +crate, we could do: + +```nix +with import <nixpkgs> {}; +((import hello.nix).hello {}).override { + crateOverrides = defaultCrateOverrides // { + libc = attrs: { buildInputs = []; }; + }; +} +``` + +### Options and phases configuration {#options-and-phases-configuration} + +Actually, the overrides introduced in the previous section are more +general. A number of other parameters can be overridden: + +- The version of `rustc` used to compile the crate: + + ```nix + (hello {}).override { rust = pkgs.rust; }; + ``` + +- Whether to build in release mode or debug mode (release mode by + default): + + ```nix + (hello {}).override { release = false; }; + ``` + +- Whether to print the commands sent to `rustc` when building + (equivalent to `--verbose` in cargo: + + ```nix + (hello {}).override { verbose = false; }; + ``` + +- Extra arguments to be passed to `rustc`: + + ```nix + (hello {}).override { extraRustcOpts = "-Z debuginfo=2"; }; + ``` + +- Phases, just like in any other derivation, can be specified using + the following attributes: `preUnpack`, `postUnpack`, `prePatch`, + `patches`, `postPatch`, `preConfigure` (in the case of a Rust crate, + this is run before calling the "build" script), `postConfigure` + (after the "build" script),`preBuild`, `postBuild`, `preInstall` and + `postInstall`. As an example, here is how to create a new module + before running the build script: + + ```nix + (hello {}).override { + preConfigure = '' + echo "pub const PATH=\"${hi.out}\";" >> src/path.rs" + ''; + }; + ``` + +### Features {#features} + +One can also supply features switches. For example, if we want to +compile `diesel_cli` only with the `postgres` feature, and no default +features, we would write: + +```nix +(callPackage ./diesel.nix {}).diesel { + default = false; + postgres = true; +} +``` + +Where `diesel.nix` is the file generated by Carnix, as explained above. + +## Setting Up `nix-shell` {#setting-up-nix-shell} + +Oftentimes you want to develop code from within `nix-shell`. Unfortunately +`buildRustCrate` does not support common `nix-shell` operations directly +(see [this issue](https://github.com/NixOS/nixpkgs/issues/37945)) +so we will use `stdenv.mkDerivation` instead. + +Using the example `hello` project above, we want to do the following: + +- Have access to `cargo` and `rustc` +- Have the `openssl` library available to a crate through it's _normal_ + compilation mechanism (`pkg-config`). + +A typical `shell.nix` might look like: + +```nix +with import <nixpkgs> {}; + +stdenv.mkDerivation { + name = "rust-env"; + nativeBuildInputs = [ + rustc cargo + + # Example Build-time Additional Dependencies + pkg-config + ]; + buildInputs = [ + # Example Run-time Additional Dependencies + openssl + ]; + + # Set Environment Variables + RUST_BACKTRACE = 1; +} +``` + +You should now be able to run the following: + +```ShellSession +$ nix-shell --pure +$ cargo build +$ cargo test +``` + +### Controlling Rust Version Inside `nix-shell` {#controlling-rust-version-inside-nix-shell} + +To control your rust version (i.e. use nightly) from within `shell.nix` (or +other nix expressions) you can use the following `shell.nix` + +```nix +# Latest Nightly +with import <nixpkgs> {}; +let src = fetchFromGitHub { + owner = "mozilla"; + repo = "nixpkgs-mozilla"; + # commit from: 2019-05-15 + rev = "9f35c4b09fd44a77227e79ff0c1b4b6a69dff533"; + sha256 = "18h0nvh55b5an4gmlgfbvwbyqj91bklf1zymis6lbdh75571qaz0"; + }; +in +with import "${src.out}/rust-overlay.nix" pkgs pkgs; +stdenv.mkDerivation { + name = "rust-env"; + buildInputs = [ + # Note: to use stable, just replace `nightly` with `stable` + latest.rustChannels.nightly.rust + + # Add some extra dependencies from `pkgs` + pkg-config openssl + ]; + + # Set Environment Variables + RUST_BACKTRACE = 1; +} +``` + +Now run: + +```ShellSession +$ rustc --version +rustc 1.26.0-nightly (188e693b3 2018-03-26) +``` + +To see that you are using nightly. + +## Using community Rust overlays {#using-community-rust-overlays} + +There are two community maintained approaches to Rust toolchain management: +- [oxalica's Rust overlay](https://github.com/oxalica/rust-overlay) +- [fenix](https://github.com/nix-community/fenix) + +Oxalica's overlay allows you to select a particular Rust version and components. +See [their documentation](https://github.com/oxalica/rust-overlay#rust-overlay) for more +detailed usage. + +Fenix is an alternative to `rustup` and can also be used as an overlay. + +Both oxalica's overlay and fenix better integrate with nix and cache optimizations. +Because of this and ergonomics, either of those community projects +should be preferred to the Mozilla's Rust overlay (`nixpkgs-mozilla`). + +### How to select a specific `rustc` and toolchain version {#how-to-select-a-specific-rustc-and-toolchain-version} + +You can consume the oxalica overlay and use it to grab a specific Rust toolchain version. +Here is an example `shell.nix` showing how to grab the current stable toolchain: +```nix +{ pkgs ? import <nixpkgs> { + overlays = [ + (import (fetchTarball "https://github.com/oxalica/rust-overlay/archive/master.tar.gz")) + ]; + } +}: +pkgs.mkShell { + nativeBuildInputs = with pkgs; [ + pkg-config + rust-bin.stable.latest.minimal + ]; +} +``` + +You can try this out by: +1. Saving that to `shell.nix` +2. Executing `nix-shell --pure --command 'rustc --version'` + +As of writing, this prints out `rustc 1.56.0 (09c42c458 2021-10-18)`. + +### How to use an overlay toolchain in a derivation {#how-to-use-an-overlay-toolchain-in-a-derivation} + +You can also use an overlay's Rust toolchain with `buildRustPackage`. +The below snippet demonstrates invoking `buildRustPackage` with an oxalica overlay selected Rust toolchain: +```nix +with import <nixpkgs> { + overlays = [ + (import (fetchTarball "https://github.com/oxalica/rust-overlay/archive/master.tar.gz")) + ]; +}; + +rustPlatform.buildRustPackage rec { + pname = "ripgrep"; + version = "12.1.1"; + nativeBuildInputs = [ + rust-bin.stable.latest.minimal + ]; + + src = fetchFromGitHub { + owner = "BurntSushi"; + repo = "ripgrep"; + rev = version; + sha256 = "1hqps7l5qrjh9f914r5i6kmcz6f1yb951nv4lby0cjnp5l253kps"; + }; + + cargoSha256 = "03wf9r2csi6jpa7v5sw5lpxkrk4wfzwmzx7k3991q3bdjzcwnnwp"; + + meta = with lib; { + description = "A fast line-oriented regex search tool, similar to ag and ack"; + homepage = "https://github.com/BurntSushi/ripgrep"; + license = licenses.unlicense; + maintainers = [ maintainers.tailhook ]; + }; +} +``` + +Follow the below steps to try that snippet. +1. create a new directory +1. save the above snippet as `default.nix` in that directory +1. cd into that directory and run `nix-build` + +### Rust overlay installation {#rust-overlay-installation} + +You can use this overlay by either changing your local nixpkgs configuration, +or by adding the overlay declaratively in a nix expression, e.g. in `configuration.nix`. +For more information see [the manual on installing overlays](#sec-overlays-install). + +### Declarative Rust overlay installation {#declarative-rust-overlay-installation} + +This snippet shows how to use oxalica's Rust overlay. +Add the following to your `configuration.nix`, `home-configuration.nix`, `shell.nix`, or similar: + +```nix +{ pkgs ? import <nixpkgs> { + overlays = [ + (import (builtins.fetchTarball "https://github.com/oxalica/rust-overlay/archive/master.tar.gz")) + # Further overlays go here + ]; + }; +}; +``` + +Note that this will fetch the latest overlay version when rebuilding your system. diff --git a/doc/languages-frameworks/texlive.section.md b/doc/languages-frameworks/texlive.section.md new file mode 100644 index 00000000000..6b505cefcc9 --- /dev/null +++ b/doc/languages-frameworks/texlive.section.md @@ -0,0 +1,129 @@ +# TeX Live {#sec-language-texlive} + +Since release 15.09 there is a new TeX Live packaging that lives entirely under attribute `texlive`. + +## User's guide {#sec-language-texlive-user-guide} + +- For basic usage just pull `texlive.combined.scheme-basic` for an environment with basic LaTeX support. + +- It typically won't work to use separately installed packages together. Instead, you can build a custom set of packages like this: + + ```nix + texlive.combine { + inherit (texlive) scheme-small collection-langkorean algorithms cm-super; + } + ``` + +- There are all the schemes, collections and a few thousand packages, as defined upstream (perhaps with tiny differences). + +- By default you only get executables and files needed during runtime, and a little documentation for the core packages. To change that, you need to add `pkgFilter` function to `combine`. + + ```nix + texlive.combine { + # inherit (texlive) whatever-you-want; + pkgFilter = pkg: + pkg.tlType == "run" || pkg.tlType == "bin" || pkg.pname == "cm-super"; + # elem tlType [ "run" "bin" "doc" "source" ] + # there are also other attributes: version, name + } + ``` + +- You can list packages e.g. by `nix repl`. + + ```ShellSession + $ nix repl + nix-repl> :l <nixpkgs> + nix-repl> texlive.collection-[TAB] + ``` + +- Note that the wrapper assumes that the result has a chance to be useful. For example, the core executables should be present, as well as some core data files. The supported way of ensuring this is by including some scheme, for example `scheme-basic`, into the combination. + +## Custom packages {#sec-language-texlive-custom-packages} + + +You may find that you need to use an external TeX package. A derivation for such package has to provide contents of the "texmf" directory in its output and provide the `tlType` attribute. Here is a (very verbose) example: + +```nix +with import <nixpkgs> {}; + +let + foiltex_run = stdenvNoCC.mkDerivation { + pname = "latex-foiltex"; + version = "2.1.4b"; + passthru.tlType = "run"; + + srcs = [ + (fetchurl { + url = "http://mirrors.ctan.org/macros/latex/contrib/foiltex/foiltex.dtx"; + sha256 = "07frz0krpz7kkcwlayrwrj2a2pixmv0icbngyw92srp9fp23cqpz"; + }) + (fetchurl { + url = "http://mirrors.ctan.org/macros/latex/contrib/foiltex/foiltex.ins"; + sha256 = "09wkyidxk3n3zvqxfs61wlypmbhi1pxmjdi1kns9n2ky8ykbff99"; + }) + ]; + + unpackPhase = '' + runHook preUnpack + + for _src in $srcs; do + cp "$_src" $(stripHash "$_src") + done + + runHook postUnpack + ''; + + nativeBuildInputs = [ texlive.combined.scheme-small ]; + + dontConfigure = true; + + buildPhase = '' + runHook preBuild + + # Generate the style files + latex foiltex.ins + + runHook postBuild + ''; + + installPhase = '' + runHook preInstall + + path="$out/tex/latex/foiltex" + mkdir -p "$path" + cp *.{cls,def,clo} "$path/" + + runHook postInstall + ''; + + meta = with lib; { + description = "A LaTeX2e class for overhead transparencies"; + license = licenses.unfreeRedistributable; + maintainers = with maintainers; [ veprbl ]; + platforms = platforms.all; + }; + }; + foiltex = { pkgs = [ foiltex_run ]; }; + + latex_with_foiltex = texlive.combine { + inherit (texlive) scheme-small; + inherit foiltex; + }; +in + runCommand "test.pdf" { + nativeBuildInputs = [ latex_with_foiltex ]; + } '' +cat >test.tex <<EOF +\documentclass{foils} + +\title{Presentation title} +\date{} + +\begin{document} +\maketitle +\end{document} +EOF + pdflatex test.tex + cp test.pdf $out +'' +``` diff --git a/doc/languages-frameworks/titanium.section.md b/doc/languages-frameworks/titanium.section.md new file mode 100644 index 00000000000..306ad866276 --- /dev/null +++ b/doc/languages-frameworks/titanium.section.md @@ -0,0 +1,110 @@ +# Titanium {#titanium} + +The Nixpkgs repository contains facilities to deploy a variety of versions of +the [Titanium SDK](https://www.appcelerator.com) versions, a cross-platform +mobile app development framework using JavaScript as an implementation language, +and includes a function abstraction making it possible to build Titanium +applications for Android and iOS devices from source code. + +Not all Titanium features supported -- currently, it can only be used to build +Android and iOS apps. + +## Building a Titanium app {#building-a-titanium-app} + +We can build a Titanium app from source for Android or iOS and for debugging or +release purposes by invoking the `titaniumenv.buildApp {}` function: + +```nix +titaniumenv.buildApp { + name = "myapp"; + src = ./myappsource; + + preBuild = ""; + target = "android"; # or 'iphone' + tiVersion = "7.1.0.GA"; + release = true; + + androidsdkArgs = { + platformVersions = [ "25" "26" ]; + }; + androidKeyStore = ./keystore; + androidKeyAlias = "myfirstapp"; + androidKeyStorePassword = "secret"; + + xcodeBaseDir = "/Applications/Xcode.app"; + xcodewrapperArgs = { + version = "9.3"; + }; + iosMobileProvisioningProfile = ./myprovisioning.profile; + iosCertificateName = "My Company"; + iosCertificate = ./mycertificate.p12; + iosCertificatePassword = "secret"; + iosVersion = "11.3"; + iosBuildStore = false; + + enableWirelessDistribution = true; + installURL = "/installipa.php"; +} +``` + +The `titaniumenv.buildApp {}` function takes the following parameters: + +* The `name` parameter refers to the name in the Nix store. +* The `src` parameter refers to the source code location of the app that needs + to be built. +* `preRebuild` contains optional build instructions that are carried out before + the build starts. +* `target` indicates for which device the app must be built. Currently only + 'android' and 'iphone' (for iOS) are supported. +* `tiVersion` can be used to optionally override the requested Titanium version + in `tiapp.xml`. If not specified, it will use the version in `tiapp.xml`. +* `release` should be set to true when building an app for submission to the + Google Playstore or Apple Appstore. Otherwise, it should be false. + +When the `target` has been set to `android`, we can configure the following +parameters: + +* The `androidSdkArgs` parameter refers to an attribute set that propagates all + parameters to the `androidenv.composeAndroidPackages {}` function. This can + be used to install all relevant Android plugins that may be needed to perform + the Android build. If no parameters are given, it will deploy the platform + SDKs for API-levels 25 and 26 by default. + +When the `release` parameter has been set to true, you need to provide +parameters to sign the app: + +* `androidKeyStore` is the path to the keystore file +* `androidKeyAlias` is the key alias +* `androidKeyStorePassword` refers to the password to open the keystore file. + +When the `target` has been set to `iphone`, we can configure the following +parameters: + +* The `xcodeBaseDir` parameter refers to the location where Xcode has been + installed. When none value is given, the above value is the default. +* The `xcodewrapperArgs` parameter passes arbitrary parameters to the + `xcodeenv.composeXcodeWrapper {}` function. This can, for example, be used + to adjust the default version of Xcode. + +When `release` has been set to true, you also need to provide the following +parameters: + +* `iosMobileProvisioningProfile` refers to a mobile provisioning profile needed + for signing. +* `iosCertificateName` refers to the company name in the P12 certificate. +* `iosCertificate` refers to the path to the P12 file. +* `iosCertificatePassword` contains the password to open the P12 file. +* `iosVersion` refers to the iOS SDK version to use. It defaults to the latest + version. +* `iosBuildStore` should be set to `true` when building for the Apple Appstore + submission. For enterprise or ad-hoc builds it should be set to `false`. + +When `enableWirelessDistribution` has been enabled, you must also provide the +path of the PHP script (`installURL`) (that is included with the iOS build +environment) to enable wireless ad-hoc installations. + +## Emulating or simulating the app {#emulating-or-simulating-the-app} + +It is also possible to simulate the correspond iOS simulator build by using +`xcodeenv.simulateApp {}` and emulate an Android APK by using +`androidenv.emulateApp {}`. diff --git a/doc/languages-frameworks/vim.section.md b/doc/languages-frameworks/vim.section.md new file mode 100644 index 00000000000..a615d585b15 --- /dev/null +++ b/doc/languages-frameworks/vim.section.md @@ -0,0 +1,348 @@ +# Vim {#vim} + +Both Neovim and Vim can be configured to include your favorite plugins +and additional libraries. + +Loading can be deferred; see examples. + +At the moment we support three different methods for managing plugins: + +- Vim packages (*recommend*) +- VAM (=vim-addon-manager) +- Pathogen +- vim-plug + +## Custom configuration {#custom-configuration} + +Adding custom .vimrc lines can be done using the following code: + +```nix +vim_configurable.customize { + # `name` specifies the name of the executable and package + name = "vim-with-plugins"; + + vimrcConfig.customRC = '' + set hidden + ''; +} +``` + +This configuration is used when Vim is invoked with the command specified as name, in this case `vim-with-plugins`. + +For Neovim the `configure` argument can be overridden to achieve the same: + +```nix +neovim.override { + configure = { + customRC = '' + # here your custom configuration goes! + ''; + }; +} +``` + +If you want to use `neovim-qt` as a graphical editor, you can configure it by overriding Neovim in an overlay +or passing it an overridden Neovimn: + +```nix +neovim-qt.override { + neovim = neovim.override { + configure = { + customRC = '' + # your custom configuration + ''; + }; + }; +} +``` + +## Managing plugins with Vim packages {#managing-plugins-with-vim-packages} + +To store you plugins in Vim packages (the native Vim plugin manager, see `:help packages`) the following example can be used: + +```nix +vim_configurable.customize { + vimrcConfig.packages.myVimPackage = with pkgs.vimPlugins; { + # loaded on launch + start = [ youcompleteme fugitive ]; + # manually loadable by calling `:packadd $plugin-name` + # however, if a Vim plugin has a dependency that is not explicitly listed in + # opt that dependency will always be added to start to avoid confusion. + opt = [ phpCompletion elm-vim ]; + # To automatically load a plugin when opening a filetype, add vimrc lines like: + # autocmd FileType php :packadd phpCompletion + }; +} +``` + +`myVimPackage` is an arbitrary name for the generated package. You can choose any name you like. +For Neovim the syntax is: + +```nix +neovim.override { + configure = { + customRC = '' + # here your custom configuration goes! + ''; + packages.myVimPackage = with pkgs.vimPlugins; { + # see examples below how to use custom packages + start = [ ]; + # If a Vim plugin has a dependency that is not explicitly listed in + # opt that dependency will always be added to start to avoid confusion. + opt = [ ]; + }; + }; +} +``` + +The resulting package can be added to `packageOverrides` in `~/.nixpkgs/config.nix` to make it installable: + +```nix +{ + packageOverrides = pkgs: with pkgs; { + myVim = vim_configurable.customize { + # `name` specifies the name of the executable and package + name = "vim-with-plugins"; + # add here code from the example section + }; + myNeovim = neovim.override { + configure = { + # add here code from the example section + }; + }; + }; +} +``` + +After that you can install your special grafted `myVim` or `myNeovim` packages. + +### What if your favourite Vim plugin isn’t already packaged? {#what-if-your-favourite-vim-plugin-isnt-already-packaged} + +If one of your favourite plugins isn't packaged, you can package it yourself: + +```nix +{ config, pkgs, ... }: + +let + easygrep = pkgs.vimUtils.buildVimPlugin { + name = "vim-easygrep"; + src = pkgs.fetchFromGitHub { + owner = "dkprice"; + repo = "vim-easygrep"; + rev = "d0c36a77cc63c22648e792796b1815b44164653a"; + sha256 = "0y2p5mz0d5fhg6n68lhfhl8p4mlwkb82q337c22djs4w5zyzggbc"; + }; + }; +in +{ + environment.systemPackages = [ + ( + pkgs.neovim.override { + configure = { + packages.myPlugins = with pkgs.vimPlugins; { + start = [ + vim-go # already packaged plugin + easygrep # custom package + ]; + opt = []; + }; + # ... + }; + } + ) + ]; +} +``` + +### Specificities for some plugins +#### Tree sitter + +By default `nvim-treesitter` encourages you to download, compile and install +the required tree-sitter grammars at run time with `:TSInstall`. This works +poorly on NixOS. Instead, to install the `nvim-treesitter` plugins with a set +of precompiled grammars, you can use `nvim-treesitter.withPlugins` function: + +```nix +(pkgs.neovim.override { + configure = { + packages.myPlugins = with pkgs.vimPlugins; { + start = [ + (nvim-treesitter.withPlugins ( + plugins: with plugins; [ + tree-sitter-nix + tree-sitter-python + ] + )) + ]; + }; + }; +}) +``` + +To enable all grammars packaged in nixpkgs, use `(pkgs.vimPlugins.nvim-treesitter.withPlugins (plugins: pkgs.tree-sitter.allGrammars))`. + +## Managing plugins with vim-plug {#managing-plugins-with-vim-plug} + +To use [vim-plug](https://github.com/junegunn/vim-plug) to manage your Vim +plugins the following example can be used: + +```nix +vim_configurable.customize { + vimrcConfig.packages.myVimPackage = with pkgs.vimPlugins; { + # loaded on launch + plug.plugins = [ youcompleteme fugitive phpCompletion elm-vim ]; + }; +} +``` + +For Neovim the syntax is: + +```nix +neovim.override { + configure = { + customRC = '' + # here your custom configuration goes! + ''; + plug.plugins = with pkgs.vimPlugins; [ + vim-go + ]; + }; +} +``` + +## Managing plugins with VAM {#managing-plugins-with-vam} + +### Handling dependencies of Vim plugins {#handling-dependencies-of-vim-plugins} + +VAM introduced .json files supporting dependencies without versioning +assuming that "using latest version" is ok most of the time. + +### Example {#example} + +First create a vim-scripts file having one plugin name per line. Example: + +```vim +"tlib" +{'name': 'vim-addon-sql'} +{'filetype_regex': '\%(vim)$', 'names': ['reload', 'vim-dev-plugin']} +``` + +Such vim-scripts file can be read by VAM as well like this: + +```vim +call vam#Scripts(expand('~/.vim-scripts'), {}) +``` + +Create a default.nix file: + +```nix +{ nixpkgs ? import <nixpkgs> {}, compiler ? "ghc7102" }: +nixpkgs.vim_configurable.customize { name = "vim"; vimrcConfig.vam.pluginDictionaries = [ "vim-addon-vim2nix" ]; } +``` + +Create a generate.vim file: + +```vim +ActivateAddons vim-addon-vim2nix +let vim_scripts = "vim-scripts" +call nix#ExportPluginsForNix({ +\ 'path_to_nixpkgs': eval('{"'.substitute(substitute(substitute($NIX_PATH, ':', ',', 'g'), '=',':', 'g'), '\([:,]\)', '"\1"',"g").'"}')["nixpkgs"], +\ 'cache_file': '/tmp/vim2nix-cache', +\ 'try_catch': 0, +\ 'plugin_dictionaries': ["vim-addon-manager"]+map(readfile(vim_scripts), 'eval(v:val)') +\ }) +``` + +Then run + +```bash +nix-shell -p vimUtils.vim_with_vim2nix --command "vim -c 'source generate.vim'" +``` + +You should get a Vim buffer with the nix derivations (output1) and vam.pluginDictionaries (output2). +You can add your Vim to your system's configuration file like this and start it by "vim-my": + +```nix +my-vim = + let plugins = let inherit (vimUtils) buildVimPluginFrom2Nix; in { + copy paste output1 here + }; in vim_configurable.customize { + name = "vim-my"; + + vimrcConfig.vam.knownPlugins = plugins; # optional + vimrcConfig.vam.pluginDictionaries = [ + copy paste output2 here + ]; + + # Pathogen would be + # vimrcConfig.pathogen.knownPlugins = plugins; # plugins + # vimrcConfig.pathogen.pluginNames = ["tlib"]; + }; +``` + +Sample output1: + +```nix +"reload" = buildVimPluginFrom2Nix { # created by nix#NixDerivation + name = "reload"; + src = fetchgit { + url = "git://github.com/xolox/vim-reload"; + rev = "0a601a668727f5b675cb1ddc19f6861f3f7ab9e1"; + sha256 = "0vb832l9yxj919f5hfg6qj6bn9ni57gnjd3bj7zpq7d4iv2s4wdh"; + }; + dependencies = ["nim-misc"]; + +}; +[...] +``` + +Sample output2: + +```nix +[ + ''vim-addon-manager'' + ''tlib'' + { "name" = ''vim-addon-sql''; } + { "filetype_regex" = ''\%(vim)$$''; "names" = [ ''reload'' ''vim-dev-plugin'' ]; } +] +``` + +## Adding new plugins to nixpkgs {#adding-new-plugins-to-nixpkgs} + +Nix expressions for Vim plugins are stored in [pkgs/applications/editors/vim/plugins](https://github.com/NixOS/nixpkgs/tree/master/pkgs/applications/editors/vim/plugins). For the vast majority of plugins, Nix expressions are automatically generated by running [`./update.py`](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/update.py). This creates a [generated.nix](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/generated.nix) file based on the plugins listed in [vim-plugin-names](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/vim-plugin-names). Plugins are listed in alphabetical order in `vim-plugin-names` using the format `[github username]/[repository]@[gitref]`. For example https://github.com/scrooloose/nerdtree becomes `scrooloose/nerdtree`. + +Some plugins require overrides in order to function properly. Overrides are placed in [overrides.nix](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/overrides.nix). Overrides are most often required when a plugin requires some dependencies, or extra steps are required during the build process. For example `deoplete-fish` requires both `deoplete-nvim` and `vim-fish`, and so the following override was added: + +```nix +deoplete-fish = super.deoplete-fish.overrideAttrs(old: { + dependencies = with super; [ deoplete-nvim vim-fish ]; +}); +``` + +Sometimes plugins require an override that must be changed when the plugin is updated. This can cause issues when Vim plugins are auto-updated but the associated override isn't updated. For these plugins, the override should be written so that it specifies all information required to install the plugin, and running `./update.py` doesn't change the derivation for the plugin. Manually updating the override is required to update these types of plugins. An example of such a plugin is `LanguageClient-neovim`. + +To add a new plugin, run `./update.py --add "[owner]/[name]"`. **NOTE**: This script automatically commits to your git repository. Be sure to check out a fresh branch before running. + +Finally, there are some plugins that are also packaged in nodePackages because they have Javascript-related build steps, such as running webpack. Those plugins are not listed in `vim-plugin-names` or managed by `update.py` at all, and are included separately in `overrides.nix`. Currently, all these plugins are related to the `coc.nvim` ecosystem of Language Server Protocol integration with vim/neovim. + +## Updating plugins in nixpkgs {#updating-plugins-in-nixpkgs} + +Run the update script with a GitHub API token that has at least `public_repo` access. Running the script without the token is likely to result in rate-limiting (429 errors). For steps on creating an API token, please refer to [GitHub's token documentation](https://docs.github.com/en/free-pro-team@latest/github/authenticating-to-github/creating-a-personal-access-token). + +```sh +GITHUB_API_TOKEN=my_token ./pkgs/applications/editors/vim/plugins/update.py +``` + +Alternatively, set the number of processes to a lower count to avoid rate-limiting. + +```sh +./pkgs/applications/editors/vim/plugins/update.py --proc 1 +``` + +## Important repositories {#important-repositories} + +- [vim-pi](https://bitbucket.org/vimcommunity/vim-pi) is a plugin repository + from VAM plugin manager meant to be used by others as well used by + +- [vim2nix](https://github.com/MarcWeber/vim-addon-vim2nix) which generates the + .nix code |