anchor.diff:  } :
   
   stdenv.mkDerivation rec {
  -  name = "cudatoolkit-4.2.9";
  +  name = "cudatoolkit-5.5.22";
   
     dontPatchELF = true;
     dontStrip = true;
  
positive.code: 
    unpackPhase = ''
      sh $src --keep --noexec
      cd pkg
    '';
  
  
negative.code:   src =
      if stdenv.system == "x86_64-linux" then
        fetchurl {
          url = http://developer.download.nvidia.com/compute/cuda/5_5/rel/installers/cuda_5.5.22_linux_64.run;
          sha256 = "b997e1dbe95704e0e806e0cedc5fd370a385351fef565c7bae0917baf3a29aa4";
        }
      else throw "cudatoolkit does not support platform ${stdenv.system}";
  
  