anchor.diff:    desmume2015 = mkLibRetroCore {
       core = "desmume2015";
       description = "libretro wrapper for desmume NDS emulator from 2015";
  -    license = gpl2;
  +    license = lib.licenses.gpl2Plus;
       extraBuildInputs = [ libpcap libGLU libGL xorg.libX11 ];
       makeFlags = lib.optional stdenv.hostPlatform.isAarch32 "platform=armv-unix"
         ++ lib.optional (!stdenv.hostPlatform.isx86) "DESMUME_JIT=0";
  
positive.code:     core = "mednafen-psx";
      src = getCoreSrc "beetle-psx";
      description = "Port of Mednafen's PSX Engine core to libretro";
      license = gpl2;
      makefile = "Makefile";
      makeFlags = [ "HAVE_HW=0" "HAVE_LIGHTREC=1" ];
    };
  
negative.code:   vecx = mkLibRetroCore {
      core = "vecx";
      description = "Port of Vecx to libretro";
      license = lib.licenses.gpl3Only;
      extraBuildInputs = [ libGL libGLU ];
    };
  
    virtualjaguar = mkLibRetroCore {
      core = "virtualjaguar";
      description = "Port of VirtualJaguar to libretro";
      license = lib.licenses.gpl3Only;
      makefile = "Makefile";
    };
  
    yabause = mkLibRetroCore {
      core = "yabause";
      description = "Port of Yabause to libretro";
      license = lib.licenses.gpl2Only;
      makefile = "Makefile";
      # Disable SSE for non-x86. DYNAREC doesn't build on either Aarch64 or x86_64.
      makeFlags = lib.optional (!stdenv.hostPlatform.isx86) "HAVE_SSE=0";
  