ut1999: fix library search paths on x86_64-linux (#332577)

    runHook postInstall

  '';

  # .so files in the SystemARM64 directory are not loaded properly on aarch64-linux

  appendRunpaths = lib.optionals (stdenv.hostPlatform.system == "aarch64-linux") [

  # Bring in game's .so files into lookup. Otherwise game fails to start

  # as: `Object not found: Class Render.Render`

  appendRunpaths = [

    "${placeholder "out"}/${systemDir}"

  ];