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6f1b1aefde
be set from the NixOS configuration. For instance, you can say
nixpkgs.config.firefox.enableGeckoMediaPlayer = true;
environment.systemPackages = [ pkgs.firefox ];
but the more interesting application is to apply global overrides to
Nixpkgs throughout NixOS, e.g.
nixpkgs.config.packageOverrides = pkgs:
{ glibc = pkgs.glibc27;
gcc = pkgs.gcc42;
};
would build the whole system with Glibc 2.7 and GCC 4.2. (There are
some issues with "useFromStdenv" in all-packages.nix that need to be
fixed for packages in the stdenv bootstrap though.)
The implementation of this option is kind of evil though due to the
need to prevent a circularity between the evaluation of
nixpkgs.config and the "pkgs" module argument.
svn path=/nixos/trunk/; revision=16866
74 lines
2.7 KiB
Nix
74 lines
2.7 KiB
Nix
# From an end-user configuration file (`configuration'), build a NixOS
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# configuration object (`config') from which we can retrieve option
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# values.
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{ configuration
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, system ? builtins.currentSystem
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, nixpkgs ? import ./from-env.nix "NIXPKGS" /etc/nixos/nixpkgs
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, pkgs ? null
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, baseModules ? import ../modules/module-list.nix
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, extraArgs ? {}
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, extraModules ? []
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}:
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let extraArgs_ = extraArgs; pkgs_ = pkgs; in
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rec {
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# These are the NixOS modules that constitute the system configuration.
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configComponents =
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[ configuration ]
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++ extraModules
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++ baseModules;
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# Merge the option definitions in all modules, forming the full
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# system configuration. This is called "configFast" because it's
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# not checked for undeclared options.
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configFast =
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pkgs.lib.definitionsOf configComponents extraArgs;
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# These are the extra arguments passed to every module. In
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# particular, Nixpkgs is passed through the "pkgs" argument.
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extraArgs = extraArgs_ // {
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inherit pkgs optionDeclarations;
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modulesPath = ../modules;
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};
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# Import Nixpkgs, allowing the NixOS option nixpkgs.config to
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# specify the Nixpkgs configuration (e.g., to set package options
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# such as firefox.enableGeckoMediaPlayer, or to apply global
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# overrides such as changing GCC throughout the system). This is
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# tricky, because we have to prevent an infinite recursion: "pkgs"
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# is passed as an argument to NixOS modules, but the value of "pkgs"
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# depends on config.nixpkgs.config, which we get from the modules.
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# So we call ourselves here with "pkgs" explicitly set to an
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# instance that doesn't depend on nixpkgs.config.
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pkgs =
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if pkgs_ != null
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then pkgs_
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else import nixpkgs {
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inherit system;
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config =
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(import ./eval-config.nix {
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inherit configuration system nixpkgs extraArgs extraModules;
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# For efficiency, leave out most NixOS modules; they don't
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# define nixpkgs.config, so it's pointless to evaluate them.
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baseModules = [ ../modules/misc/nixpkgs.nix ];
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pkgs = import nixpkgs { inherit system; config = {}; };
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}).configFast.nixpkgs.config;
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};
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# "fixableDeclarationsOf" is used instead of "declarationsOf" because some
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# option default values may depends on the definition of other options.
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# !!! This seems inefficent. Didn't definitionsOf already compute
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# the option declarations?
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optionDeclarations =
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pkgs.lib.fixableDeclarationsOf configComponents extraArgs configFast;
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# Optionally check wether all config values have corresponding
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# option declarations.
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config = pkgs.checker configFast
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configFast.environment.checkConfigurationOptions
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optionDeclarations configFast;
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}
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