anchor.diff:    passthru = {inherit libdrm;};
     
     meta = {
  -    description = "OpenGL-compatible 3D library. Supports acceleration.";
  +    description = "An open source implementation of OpenGL";
       homepage = http://www.mesa3d.org/;
     };
   }
  
positive.code:   
    preBuild = "
      makeFlagsArray=(INSTALL_DIR=$out DRI_DRIVER_INSTALL_DIR=$out/lib/modules/dri SHELL=$SHELL)
    ";
    
    buildInputs = [
  
negative.code:     if stdenv.system == "x86_64-linux" then "linux-dri-x86-64" else
      abort "unsupported platform for Mesa"; # !!! change to throw, remove all the mesa asserts in all-packages.nix
  
    # Missing file in 7.0.2. Can be removed for >= 7.0.3.
    missingPC = fetchurl {
      url = "http://sources.gentoo.org/viewcvs.py/*checkout*/gentoo-x86/media-libs/mesa/files/7.0.2-glw.pc.in?rev=1.1";
      sha256 = "1z4d50pllwi8g6n567dk3zxq4qmam79n72wr55mdqx0jrdj4fj0v";
    };
      
  in
  
  stdenv.mkDerivation {
    name = "mesa-7.0.2";
    
    src = fetchurl {
      url = mirror://sourceforge/mesa3d/MesaLib-7.0.2.tar.bz2;
      md5 = "93e6ed7924ff069a4f883b4fce5349dc";
    };
  /*    (fetchurl {
        url = http://nix.cs.uu.nl/dist/tarballs/MesaGLUT-6.4.tar.bz2;
  