{ config, options, lib, pkgs, ... }: with lib; let cfg = config.nixpkgs; opt = options.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 recursiveUpdate 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 = x: let traceXIfNot = c: if c x then true else lib.traceSeqN 1 x false; in traceXIfNot isConfig; merge = args: foldr (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; }; defaultPkgs = import ../../.. { inherit (cfg) config overlays localSystem crossSystem; }; finalPkgs = if opt.pkgs.isDefined then cfg.pkgs.appendOverlays cfg.overlays else defaultPkgs; in { options.nixpkgs = { pkgs = mkOption { defaultText = literalExpression '' import "''${nixos}/.." { inherit (cfg) config overlays localSystem crossSystem; } ''; type = pkgsType; example = literalExpression "import <nixpkgs> {}"; description = '' If set, the pkgs argument to all NixOS modules is the value of this option, extended with <code>nixpkgs.overlays</code>, if that is also set. Either <code>nixpkgs.crossSystem</code> or <code>nixpkgs.localSystem</code> will be used in an assertion to check that the NixOS and Nixpkgs architectures match. Any other options in <code>nixpkgs.*</code>, notably <code>config</code>, will be ignored. If unset, the pkgs argument to all NixOS modules is determined as shown in the default value for this option. 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 = literalExpression '' { 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 = literalExpression '' [ (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. Each function in the list 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. If <code>nixpkgs.pkgs</code> is set, overlays specified here will be applied after the overlays that were already present in <code>nixpkgs.pkgs</code>. ''; }; localSystem = mkOption { type = types.attrs; # TODO utilize lib.systems.parsedPlatform default = { inherit (cfg) system; }; example = { system = "aarch64-linux"; config = "aarch64-unknown-linux-gnu"; }; # Make sure that the final value has all fields for sake of other modules # referring to this. TODO make `lib.systems` itself use the module system. apply = lib.systems.elaborate; defaultText = literalExpression ''(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"; }; 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.localSystem</code> is set. Ignored when <code>nixpkgs.pkgs</code> is set. ''; }; initialSystem = mkOption { type = types.str; internal = true; description = '' Preserved value of <literal>system</literal> passed to <literal>eval-config.nix</literal>. ''; }; }; config = { _module.args = { pkgs = finalPkgs; }; assertions = [ ( let nixosExpectedSystem = if config.nixpkgs.crossSystem != null then config.nixpkgs.crossSystem.system or (lib.systems.parse.doubleFromSystem (lib.systems.parse.mkSystemFromString config.nixpkgs.crossSystem.config)) else config.nixpkgs.localSystem.system or (lib.systems.parse.doubleFromSystem (lib.systems.parse.mkSystemFromString config.nixpkgs.localSystem.config)); nixosOption = if config.nixpkgs.crossSystem != null then "nixpkgs.crossSystem" else "nixpkgs.localSystem"; pkgsSystem = finalPkgs.stdenv.targetPlatform.system; in { assertion = nixosExpectedSystem == pkgsSystem; message = "The NixOS nixpkgs.pkgs option was set to a Nixpkgs invocation that compiles to target system ${pkgsSystem} but NixOS was configured for system ${nixosExpectedSystem} via NixOS option ${nixosOption}. The NixOS system settings must match the Nixpkgs target system."; } ) ]; }; }