{
  lib,
  pkgs,
  test,
  ...
}:
if test then
  { }
else
  {
    nixpkgs = lib.mkIf (!test) (
      lib.mkForce {
        file = {
          path = toString (
            pkgs.fetchFromGitHub {
              owner = "nixos";
              repo = "nixpkgs";
              rev = (lib.importJSON ../../../krebs/nixpkgs.json).rev;
              sha256 = (lib.importJSON ../../../krebs/nixpkgs.json).sha256;
            }
          );
          useChecksum = true;
        };
      }
    );
    nixpkgs-unstable = lib.mkForce {
      file.path = "/var/empty";
    };
  }