rust: update cargo builder to fetch registry dynamically

The biggest benefit is that we no longer have to update the registry
package. This means that just about any cargo package can be built by
nix. No longer does `cargo update` need to be feared because it will
update to packages newer then what is available in nixpkgs.

Instead of fetching the cargo registry this bundles all the source code
into a "vendor/" folder.

This also uses the new --frozen and --locked flags which is nice.

Currently cargo-vendor only provides binaries for Linux and
macOS 64-bit. This can be solved by building it for the other
architectures and uploading it somewhere (like the NixOS cache).

This also has the downside that it requires a change to everyone's deps
hash. And if the old one is used because it was cached it will fail to
build as it will attempt to use the old version. For this reason the
attribute has been renamed to `cargoSha256`.

Authors:
* Kevin Cox <kevincox@kevincox.ca>
* Jörg Thalheim <Mic92@users.noreply.github.com>
* zimbatm <zimbatm@zimbatm.com>

1 files changed, 10 insertions, 11 deletions

diff --git a/doc/languages-frameworks/rust.md b/doc/languages-frameworks/rust.md
index 481b76fb78f..276b5496fbb 100644
--- a/doc/languages-frameworks/rust.md
+++ b/doc/languages-frameworks/rust.md
@@ -9,16 +9,15 @@ date: 2017-03-05
 To install the rust compiler and cargo put
 
 ```
-rustStable.rustc
-rustStable.cargo
+rust
 ```
 
-into the `environment.systemPackages` or bring them into scope with
-`nix-shell -p rustStable.rustc -p rustStable.cargo`.
+into the `environment.systemPackages` or bring them into
+scope with `nix-shell -p rust`.
 
-There are also `rustBeta` and `rustNightly` package sets available.
-These are not updated very regularly. For daily builds use either rustup from
-nixpkgs or use the [Rust nightlies overlay](#using-the-rust-nightlies-overlay).
+For daily builds (beta and nightly) use either rustup from
+nixpkgs or use the [Rust nightlies
+overlay](#using-the-rust-nightlies-overlay).
 
 ## Packaging Rust applications
 
@@ -38,7 +37,7 @@ buildRustPackage rec {
     sha256 = "0y5d1n6hkw85jb3rblcxqas2fp82h3nghssa4xqrhqnz25l799pj";
   };
 
-  depsSha256 = "0q68qyl2h6i0qsz82z840myxlnjay8p1w5z7hfyr8fqp7wgwa9cx";
+  cargoSha256 = "0q68qyl2h6i0qsz82z840myxlnjay8p1w5z7hfyr8fqp7wgwa9cx";
 
   meta = with stdenv.lib; {
     description = "A utility that combines the usability of The Silver Searcher with the raw speed of grep";
@@ -50,7 +49,7 @@ buildRustPackage rec {
 }
 ```
 
-`buildRustPackage` requires a `depsSha256` attribute which is computed over
+`buildRustPackage` requires a `cargoSha256` attribute which is computed over
 all crate sources of this package. Currently it is obtained by inserting a
 fake checksum into the expression and building the package once. The correct
 checksum can be then take from the failed build.
@@ -76,11 +75,11 @@ in the `~/.config/nixpkgs/overlays` directory.
 
 The latest version can be installed with the following command:
 
-    $ nix-env -Ai nixos.rustChannels.stable.rust
+    $ nix-env -Ai nixos.latest.rustChannels.stable.rust
 
 Or using the attribute with nix-shell:
 
-    $ nix-shell -p nixos.rustChannels.stable.rust
+    $ nix-shell -p nixos.latest.rustChannels.stable.rust
 
 To install the beta or nightly channel, "stable" should be substituted by
 "nightly" or "beta", or