rec {

  mkPkgs = src: let

    normalPkgs = (import src) {};

    config = {
      allowUnfree = true;
      packageOverrides = pkgs: {
        nixgl = (import ./nix/nixgl.nix) pkgs;
        ldUtils = (import ./nix/ld-utils.nix) pkgs;
      };
    };

  in pkgsArg: (import src) (
    normalPkgs.lib.attrsets.recursiveUpdate { config = config; } pkgsArg
  );

  stable = mkPkgs (builtins.fetchTarball {
    name = "nixpkgs-2405";
    url = "https://github.com/nixos/nixpkgs/archive/63dacb46bf939521bdc93981b4cbb7ecb58427a0.tar.gz";
    sha256 = "sha256:1lr1h35prqkd1mkmzriwlpvxcb34kmhc9dnr48gkm8hh089hifmx";
  });

  unstable = mkPkgs (builtins.fetchTarball {
    name = "nixpkgs-2411-beta";
    url = "https://github.com/nixos/nixpkgs/archive/8b27c1239e5c421a2bbc2c65d52e4a6fbf2ff296.tar.gz";
    sha256 = "sha256:1gx0hihb7kcddv5h0k7dysp2xhf1ny0aalxhjbpj2lmvj7h9g80a";
  });
}