Pass specialArgs to the home-manager module

Hi,

I’m learning nix with this awesome book someone here showed me and I’m struggling with a notion explained in it:

I’m learning what nix modules are and how I could use them to modularize my configuration. However I’m have issues when using the ‘specialArgs’ variable described in the book as a variable to pass extra arguments to all modules.

It works perfectly when I try to define it to pass arguments to the configuration.nix module when building my system-wide configuration, but nix complains about it being unexpected when defining it for the homeManagerConfiguration modules.

Here is the flake:

Summary
{
  description = "JM445's Nix system configuration flake";

  inputs = {
    nixpkgs.url = "nixpkgs/nixos-23.05";
    home-manager.url = "github:nix-community/home-manager/release-23.05";
    home-manager.inputs.nixpkgs.follows = "nixpkgs";
    nixpie.url = "git+https://gitlab.cri.epita.fr/cri/infrastructure/nixpie.git";
  };

  outputs = inputs@{ nixpkgs, home-manager, nixpie, ... }:
    let
      system = "x86_64-linux";

      pkgs = import nixpkgs {
        inherit system;
        config = {allowUnfree = true;};
      };

      lib = nixpkgs.lib;

      nixpiepkg = nixpie.packages.${system};

    in {
      homeManagerConfigurations = {
        jm445 = home-manager.lib.homeManagerConfiguration {
          inherit pkgs;
          specialArgs = {nixpie = nixpiepkg;}; # This raise an error
          modules = [
            ./user/home.nix
            {
              home = {
                username = "jm445";
                homeDirectory = "/home/jm445";
              };
            }
          ];
        };
      };

      nixosConfigurations = {
        nixos = lib.nixosSystem {
          inherit system;
          specialArgs = {nixpie = nixpiepkg;}; # This works as expected
          modules = [
            ./system/configuration.nix
          ];
        };
      };
    };
}

When passing my specialArgs to nixosSystem modules, I am able to install a package that is inside ‘nixpie’ but I would prefer to install it at the user level with home manager.

What am I missing ?

Thank’s,

JM

1 Like

I don’t know why, but I believe home-manager uses extraSpecialArgs for this purpose, so try that.

2 Likes

Okay that works. This is really confusing but thank you for the help !

JM

1 Like

Use extraSpecialArgs instead of specialArgs

forAllUser (name: home-manager.lib.homeManagerConfiguration {

  pkgs = (nixpkgs.legacyPackages.${system}.extend (import ./overlays/default.nix));

  # Specify your home configuration modules here, for example,
  # the path to your home.nix.

  modules = [ ./home-module.nix ];

  # Optionally use extraSpecialArgs
  # to pass through arguments to home.nix

  extraSpecialArgs = {
    userConfig = {
      home = "/home/${name}";
      inherit name;
      inherit system;
    };
  };

})