NIX.md

nix integration for XMonad

Customizing the nix-shell

It's possible to use a file develop.nix to customize the devShell provided by the flake. This is useful if e.g. you want to have the haskell-language-server or other developer tools in the shell properly configured (correct GHC versions, and the like).

Here is an example develop.nix for haskell-language-server:

pkgs: devInputs: devInputs // {
  nativeBuildInputs = with pkgs.haskellPackages;
    [ cabal-install hlint ghcid ormolu implicit-hie haskell-language-server ];
}

NixOS Modules

The core and contrib flakes provide NixOS configuration modules. You can bring them into your system flake like so:

{
  inputs = {
    nixpkgs.url = github:NixOS/nixpkgs/nixos-<version>;
    xmonad.url = github:xmonad/xmonad;
    xmonad-contrib.url = github:xmonad/xmonad-contrib;
  };

  outputs = { self, nixpkgs, xmonad, xmonad-contrib }: {
    nixosConfigurations.<hostname> = nixpkgs.lib.nixosSystem rec {
      system = <arch>;
      modules = [
        ./configuration.nix
        xmonad.nixosModule
        xmonad-contrib.nixosModule
      ];
    };
  };
}

Then you can set the provided options in your configuration.nix under flake:

  services.xserver.windowManager.xmonad = {
    enable = true;
    enableContribAndExtras = true;
    flake = {
      enable = true;
    # prefix = "unstable";
      compiler = "ghc921";
    };
  };

This will use core and contrib from git for your system xmonad, building your config with the compiler of your choice.

With the flake enabled, the xmonad.haskellPackages option is not used directly, and is instead set by the flake.compiler option. When compiler is unset, the default pkgs.haskellPackages is used.

The prefix option is used if you wish to select your haskell packages from within, e.g., unstable overlaid into pkgs as pkgs.unstable.

See the flakes themselves and nix flake documentation for full detail.