anchor.diff:  , fetchTritonPatch
   , fetchurl
   , flex
  +, gettext
   , intltool
  -, python2
   , python2Packages
  -, substituteAll
  -
  -#, libxml2Python
   
   , expat
  -, file
  +#, file
   , libclc
   , libdrm
   , libelf
   , libffi
  +, libglvnd
   , libomxil-bellagio
   #, libva
   , libvdpau
   , llvm
  +, openssl
   , systemd_lib
   , wayland
   , xorg
  
positive.code:       "https://launchpad.net/mesa/trunk/${version}/+download/mesa-${version}.tar.xz"
      ];
      allowHashOutput = false;  # Provided by upstream directly
      sha256 = "40e148812388ec7c6d7b6657d5a16e2e8dabba8b97ddfceea5197947647bdfb4";
    };
  
    nativeBuildInputs = [
      autoreconfHook
      bison
      file
      flex
      intltool
      python2
      python2Packages.Mako
      xorg.makedepend
    ];
  
negative.code:     libdrm
      libelf
      libffi
      libglvnd
      libomxil-bellagio
      # FIXME: recursive dependency
      #libva
      libvdpau
      llvm
      openssl
      systemd_lib
      wayland
      xorg.dri2proto
      xorg.dri3proto
      xorg.glproto
      xorg.libpthreadstubs
      xorg.libX11
      xorg.libxcb
      xorg.libXdamage
  