{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.nixpkgs;
isConfig = x:
builtins.isAttrs x || lib.isFunction x;
optCall = f: x:
if lib.isFunction f
then f x
else f;
mergeConfig = lhs_: rhs_:
let
lhs = optCall lhs_ { inherit pkgs; };
rhs = optCall rhs_ { inherit pkgs; };
in
lhs // rhs //
optionalAttrs (lhs ? packageOverrides) {
packageOverrides = pkgs:
optCall lhs.packageOverrides pkgs //
optCall (attrByPath ["packageOverrides"] ({}) rhs) pkgs;
} //
optionalAttrs (lhs ? perlPackageOverrides) {
perlPackageOverrides = pkgs:
optCall lhs.perlPackageOverrides pkgs //
optCall (attrByPath ["perlPackageOverrides"] ({}) rhs) pkgs;
};
configType = mkOptionType {
name = "nixpkgs-config";
description = "nixpkgs config";
check = traceValIfNot isConfig;
merge = args: fold (def: mergeConfig def.value) {};
};
overlayType = mkOptionType {
name = "nixpkgs-overlay";
description = "nixpkgs overlay";
check = lib.isFunction;
merge = lib.mergeOneOption;
};
pkgsType = mkOptionType {
name = "nixpkgs";
description = "An evaluation of Nixpkgs; the top level attribute set of packages";
check = builtins.isAttrs;
};
in
{
options.nixpkgs = {
pkgs = mkOption {
defaultText = literalExample
''import "''${nixos}/.." {
inherit (config.nixpkgs) config overlays localSystem crossSystem;
}
'';
default = import ../../.. {
localSystem = { inherit (cfg) system; } // cfg.localSystem;
inherit (cfg) config overlays crossSystem;
};
type = pkgsType;
example = literalExample ''import <nixpkgs> {}'';
description = ''
This is the evaluation of Nixpkgs that will be provided to
all NixOS modules. Defining this option has the effect of
ignoring the other options that would otherwise be used to
evaluate Nixpkgs, because those are arguments to the default
value. The default value imports the Nixpkgs source files
relative to the location of this NixOS module, because
NixOS and Nixpkgs are distributed together for consistency,
so the <code>nixos</code> in the default value is in fact a
relative path. The <code>config</code>, <code>overlays</code>,
<code>localSystem</code>, and <code>crossSystem</code> come
from this option's siblings.
This option can be used by applications like NixOps to increase
the performance of evaluation, or to create packages that depend
on a container that should be built with the exact same evaluation
of Nixpkgs, for example. Applications like this should set
their default value using <code>lib.mkDefault</code>, so
user-provided configuration can override it without using
<code>lib</code>.
Note that using a distinct version of Nixpkgs with NixOS may
be an unexpected source of problems. Use this option with care.
'';
};
config = mkOption {
default = {};
example = literalExample
''
{ allowBroken = true; allowUnfree = true; }
'';
type = configType;
description = ''
The configuration of the Nix Packages collection. (For
details, see the Nixpkgs documentation.) It allows you to set
package configuration options.
Ignored when <code>nixpkgs.pkgs</code> is set.
'';
};
overlays = mkOption {
default = [];
example = literalExample
''
[ (self: super: {
openssh = super.openssh.override {
hpnSupport = true;
kerberos = self.libkrb5;
};
};
) ]
'';
type = types.listOf overlayType;
description = ''
List of overlays to use with the Nix Packages collection.
(For details, see the Nixpkgs documentation.) It allows
you to override packages globally. This is a function that
takes as an argument the <emphasis>original</emphasis> Nixpkgs.
The first argument should be used for finding dependencies, and
the second should be used for overriding recipes.
Ignored when <code>nixpkgs.pkgs</code> is set.
'';
};
localSystem = mkOption {
type = types.attrs; # TODO utilize lib.systems.parsedPlatform
default = { system = builtins.currentSystem; };
example = { system = "aarch64-linux"; config = "aarch64-unknown-linux-gnu"; };
defaultText = literalExample
''(import "''${nixos}/../lib").lib.systems.examples.aarch64-multiplatform'';
description = ''
Specifies the platform on which NixOS should be built. When
<code>nixpkgs.crossSystem</code> is unset, it also specifies
the platform <emphasis>for</emphasis> which NixOS should be
built. If this option is unset, it defaults to the platform
type of the machine where evaluation happens. Specifying this
option is useful when doing distributed multi-platform
deployment, or when building virtual machines. See its
description in the Nixpkgs manual for more details.
Ignored when <code>nixpkgs.pkgs</code> is set.
'';
};
crossSystem = mkOption {
type = types.nullOr types.attrs; # TODO utilize lib.systems.parsedPlatform
default = null;
example = { system = "aarch64-linux"; config = "aarch64-unknown-linux-gnu"; };
defaultText = literalExample
''(import "''${nixos}/../lib").lib.systems.examples.aarch64-multiplatform'';
description = ''
Specifies the platform for which NixOS should be
built. Specify this only if it is different from
<code>nixpkgs.localSystem</code>, the platform
<emphasis>on</emphasis> which NixOS should be built. In other
words, specify this to cross-compile NixOS. Otherwise it
should be set as null, the default. See its description in the
Nixpkgs manual for more details.
Ignored when <code>nixpkgs.pkgs</code> is set.
'';
};
system = mkOption {
type = types.str;
example = "i686-linux";
description = ''
Specifies the Nix platform type on which NixOS should be built.
It is better to specify <code>nixpkgs.localSystem</code> instead.
<programlisting>
{
nixpkgs.system = ..;
}
</programlisting>
is the same as
<programlisting>
{
nixpkgs.localSystem.system = ..;
}
</programlisting>
See <code>nixpkgs.localSystem</code> for more information.
Ignored when <code>nixpkgs.pkgs</code> is set.
'';
};
};
config = {
_module.args = {
pkgs = cfg.pkgs;
pkgs_i686 = cfg.pkgs.pkgsi686Linux;
};
};
}