anchor.diff:  */
   
   let
  -  version = "10.1.5";
  +  version = "10.2.2";
     # this is the default search path for DRI drivers
     driverLink = "/run/opengl-driver" + stdenv.lib.optionalString stdenv.isi686 "-32";
   in
  
positive.code: 
    src =  fetchurl {
      url = "ftp://ftp.freedesktop.org/pub/mesa/${version}/MesaLib-${version}.tar.bz2";
      sha256 = "1g2vy7zaamzs00xasiwg0d6cb5sclfd9v8jms14ll9bghg3mwv5w";
    };
  
    prePatch = "patchShebangs .";
  
negative.code:     "--enable-glx-tls"
      "--enable-shared-glapi" "--enable-shared-gallium"
      "--enable-driglx-direct" # seems enabled anyway
      "--enable-gallium-llvm" "--enable-llvm-shared-libs"
      "--enable-xa" # used in vmware driver
      "--enable-gles1" "--enable-gles2"
      "--enable-vdpau"
  