nixos-config/system/steam.nix

{ config, pkgs, inputs, ... }:
let
  pkgs' = import inputs.nixpkgs-fixed-steam {
    inherit (pkgs) system config;
  };
in
{
  programs.steam.enable = true;
  programs.steam.package = pkgs'.steam.override {
    extraLibraries = pkgs: with config.hardware.opengl;
      if pkgs.hostPlatform.is64bit
      then [ package ] ++ extraPackages
      else [ package32 ] ++ extraPackages32;

    extraPkgs = pkgs: with pkgs; [
      capitaine-cursors
      bibata-cursors
      mangohud
      xdg-user-dirs
    ];
  };
  environment.systemPackages = with pkgs; [
    protontricks
  ];
}