anchor.diff:  
     whisper = buildPythonPackage rec {
       name = "whisper-${version}";
  -    version = "0.9.12";
  +    version = graphiteVersion;
   
       src = pkgs.fetchurl {
         url = "mirror://pypi/w/whisper/${name}.tar.gz";
  -      sha256 = "0eca66449d6ceb29e2ab5457b01618e0fe525710dd130a286a18282d849ae5b2";
  +      sha256 = "1chkphxwnwvy2cs7jc2h2i0lqqvi9jx6vqj3ly88lwk7m35r4ss2";
       };
   
       # error: invalid command 'test'
  
positive.code:   graphite_web = buildPythonPackage rec {
      name = "graphite-web-${version}";
      disabled = isPy3k;
      version = "0.9.15";
  
      src = pkgs.fetchurl rec {
        url = "mirror://pypi/g/graphite-web/${name}.tar.gz";
  
negative.code: 
    carbon = buildPythonPackage rec {
      name = "carbon-${version}";
      version = graphiteVersion;
  
      src = pkgs.fetchurl {
        url = "mirror://pypi/c/carbon/${name}.tar.gz";
  