anchor.diff:    graphite_web = buildPythonPackage rec {
       name = "graphite-web-${version}";
       disabled = isPy3k;
  -    version = "0.9.15";
  +    version = graphiteVersion;
   
       src = pkgs.fetchurl rec {
         url = "mirror://pypi/g/graphite-web/${name}.tar.gz";
  
positive.code:   });
  
    buildPythonApplication = args: buildPythonPackage ({namePrefix="";} // args );
  
  in {
  
  
negative.code: 
    carbon = buildPythonPackage rec {
      name = "carbon-${version}";
      version = graphiteVersion;
  
      src = pkgs.fetchurl {
        url = "mirror://pypi/c/carbon/${name}.tar.gz";
  