{
    inputs,
    system,
    ...
  }: final: prev: {
    unstable = import inputs.nixpkgs-unstable {
        inherit system;
        config.allowUnfree = true;
    };

    betacraft = prev.pkgs.callPackage ./packages/betacraft.nix {};

    unciv = prev.unciv.overrideAttrs (old: rec {
        version = "4.18.14";
        src = prev.fetchurl {
          url = "https://github.com/yairm210/Unciv/releases/download/${version}-patch1/Unciv.jar";
          hash = "sha256-ykyHaIxnahC8D8ZAqzGnwNhc7mUX25uO4hEWKz+7p7o=";
        };
    });

    cataclysm-dda-indigo = prev.cataclysm-dda.overrideAttrs (old: {
      version = "0.I";
      src = prev.fetchFromGitHub {
        owner = "CleverRaven";
        repo = "Cataclysm-DDA";
        rev = "${final.cataclysm-dda-indigo.version}-branch";
        hash = "sha256-FA1ivcg+8JBKs9AM0l2iyYE7wAT7IIlnzRp+fCIomso=";
      };
      patches = [];
    });
}