anchor.diff:      src = getCoreSrc core;
       description = "Neko Project II kai libretro port";
       license = lib.licenses.mit;
  -    makefile = "Makefile.libretro";
       makeFlags = [
         # See https://github.com/AZO234/NP2kai/tags
         "NP2KAI_VERSION=rev.22"
  
positive.code:     description = "Port of Hatari to libretro";
      license = lib.licenses.gpl2Only;
      extraBuildInputs = [ SDL zlib ];
      extraNativeBuildInputs = [ cmake which ];
      dontUseCmakeConfigure = true;
      dontConfigure = true;
      makeFlags = [ "EXTERNAL_ZLIB=1" ];
      depsBuildBuild = [ stdenv.cc ];
    };
  
    mame = mkLibRetroCore {
  
negative.code:     description = "Port of MAME to libretro";
      license = with lib.licenses; [ bsd3 gpl2Plus ];
      extraBuildInputs = [ alsa-lib libGLU libGL portaudio python3 xorg.libX11 ];
    };
  
    mame2000 = mkLibRetroCore {
  