anchor.diff:      + stdenv.lib.optionalString enableTextureFloats " --enable-texture-float";
   
     buildInputs = [
  -    autoconf automake libtool expat libxml2Python udev llvm
  +    autoconf automake libtool intltool expat libxml2Python udev llvm
       libdrm libXxf86vm libXfixes libXdamage glproto dri2proto libX11 libXext libxcb libXt
     ];
   
  
positive.code: else
  
  let
    version = "9.0.3";
  in
  stdenv.mkDerivation {
    name = "mesa-${version}";
  
    src = fetchurl {
      url = "ftp://ftp.freedesktop.org/pub/mesa/${version}/MesaLib-${version}.tar.bz2";
      sha256="1986av3pl8v9hhxxqqdm2wn3qlwwnrznvfmm4wszhyf3n82h157a";
    };
  
    prePatch = "patchShebangs .";
  
negative.code: { stdenv, fetchurl, flex, bison, pkgconfig, intltool, libdrm, file, expat, makedepend
  , libXxf86vm, libXfixes, libXdamage, glproto, dri2proto, libX11, libxcb, libXext
  , libXt, udev, enableTextureFloats ? false, enableR600LlvmCompiler ? false
  , python, libxml2Python, autoconf, automake, libtool, llvm, writeText }:
  