{ pkgs, nixpkgs, nixng, globals, ... }: {
  mkNixNGImage = name: file:
    let
      stream = (import file {
        inherit nixpkgs nixng globals;
        inherit (nixng) nglib;
      }).config.system.build.ociImage.stream;
    in
    pkgs.stdenv.mkDerivation {
      name = "${name}.tar";
      src = stream;
      dontUnpack = true;
      buildPhase = ''
        $src > $out
      '';
    };

  nixSnapshotterRef = imagePath: "nix:0${imagePath}";
}