anchor.diff:  */
   
   let
  -  version = "10.0.4";
  +  version = "10.1.1";
     # this is the default search path for DRI drivers
     driverLink = "/run/opengl-driver" + stdenv.lib.optionalString stdenv.isi686 "-32";
   in
  
positive.code:     ;
    buildInputs = with xorg; [
      autoreconfHook intltool expat libxml2Python llvm
      libXfixes glproto dri2proto libX11 libXext libxcb libXt
      libffi wayland libvdpau libelf
    ] ++ optionals enableExtraFeatures [ /*libXvMC*/ ]
      ++ optional stdenv.isLinux udev
  
negative.code: 
    src =  fetchurl {
      url = "ftp://ftp.freedesktop.org/pub/mesa/${version}/MesaLib-${version}.tar.bz2";
      sha256 = "1c4qcz7zi3qvdcxa56yxl6kps5amk4zq2xlhqlgcpzqzv0777bpk";
    };
  
    prePatch = "patchShebangs .";
  