anchor.diff:      };
       description = "Port of Meteor to libretro";
       license = gpl3;
  -  }).override {
  -    makefile = "Makefile";
  -    preConfigure = "cd libretro";
  +    makefile = "Makefile";
  +    preBuild = "cd libretro";
     };
   
     mgba = mkLibRetroCore rec {
  
positive.code:     };
      description = "Port of Game and Watch to libretro";
      license = zlib;
    }).override {
      makefile = "Makefile";
      dontConfigure = true;
    };
  
    handy = (mkLibRetroCore rec {
      core = "handy";
      src = fetchRetro {
        repo = "libretro-" + core;
  
negative.code:     };
      description = "Port of Play! to libretro";
      license = bsd2;
      extraBuildInputs = [ boost ];
      extraNativeBuildInputs = [ cmake openssl curl icu libGL libGLU xorg.libX11 ];
      makefile = "Makefile";
      cmakeFlags = [ "-DBUILD_PLAY=OFF -DBUILD_LIBRETRO_CORE=ON" ];
      postBuild = "mv Source/ui_libretro/play_libretro${stdenv.hostPlatform.extensions.sharedLibrary} play_libretro${stdenv.hostPlatform.extensions.sharedLibrary}";
    };
  
    ppsspp = mkLibRetroCore {
      core = "ppsspp";
      src = fetchgit {
        url = "https://github.com/hrydgard/ppsspp";
  