anchor.diff:        "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 = "0c4yskqwmh5k0wavjrkfcldafvnpcx8gjcx584bscxks69krd789";
  +    sha256 = "1ydivzm4c2k53b65lvm11d62z140xlmd7viw63bl5cm5idjg02q7";
     };
   
     prePatch = "patchShebangs .";
  
positive.code: in
  
  let
    version = "18.0.3";
    branch  = head (splitString "." version);
  in
  
  
negative.code: , pkgconfig, intltool, autoreconfHook, substituteAll
  , file, expat, libdrm, xorg, wayland, wayland-protocols, openssl
  , llvmPackages, libffi, libomxil-bellagio, libva-minimal
  , libelf, libvdpau, valgrind-light, python2, python27Packages
  , libglvnd
  , grsecEnabled ? false
  , enableRadv ? true
  