anchor.diff:  , pkgconfig, intltool, autoreconfHook, substituteAll
   , file, expat, libdrm, xorg, wayland, wayland-protocols, openssl
   , llvmPackages, libffi, libomxil-bellagio, libva-minimal
  -, libelf, libvdpau, valgrind-light, python2
  +, libelf, libvdpau, valgrind-light, python2, python27Packages
   , libglvnd
   , grsecEnabled ? false
   , enableRadv ? true
  
positive.code:     libX11 libXext libxcb libXt libXfixes libxshmfence
      libffi wayland wayland-protocols libvdpau libelf libXvMC
      libomxil-bellagio libva-minimal libpthreadstubs openssl/*or another sha1 provider*/
      valgrind-light python2
    ];
  
    enableParallelBuilding = true;
  
negative.code:       "ftp://ftp.freedesktop.org/pub/mesa/older-versions/${branch}.x/${version}/mesa-${version}.tar.xz"
        "https://mesa.freedesktop.org/archive/mesa-${version}.tar.xz"
      ];
      sha256 = "1ydivzm4c2k53b65lvm11d62z140xlmd7viw63bl5cm5idjg02q7";
    };
  
    prePatch = "patchShebangs .";
  