anchor.diff:    };
   
     guessit = buildPythonPackage rec {
  -    version = "0.9.3";
  +    version = "0.9.4";
       name = "guessit-${version}";
       disabled = isPy3k;
   
       src = pkgs.fetchurl {
         url = "http://pypi.python.org/packages/source/g/guessit/${name}.tar.gz";
  -      sha256 = "16kbxdz5zm3mfn739ynis04zw76x2gn1lz5d7vcwh8hzaj16yyk6";
  +      sha256 = "068d3dmyk4v04p2zna0340lsdnpkm10gyza62apd9akgjh9rfs48";
       };
   
       propagatedBuildInputs = with self; [
  -      dateutil_1_5 requests stevedore babelfish pyyaml
  +      dateutil_2_1 requests stevedore babelfish pyyaml
       ];
   
       # A unicode test fails
  
positive.code:     src = pkgs.fetchurl {
        url = "http://pypi.python.org/packages/source/p/python-dateutil/python-${name}.tar.gz";
        sha256 = "02dhw57jf5kjcp7ng1if7vdrbnlpb9yjmz7wygwwvf3gni4766bg";
      };
  
      propagatedBuildInputs = with self; [ self.six ];
  
negative.code: 
  
    apscheduler = buildPythonPackage rec {
      name = "APScheduler-3.0.1";
  
      propagatedBuildInputs = with self; [ futures tzlocal six pytest mock sqlalchemy9 ];
  
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/A/APScheduler/${name}.tar.gz";
        sha256 = "1dcyk58svhhd7flpq0fbyzcp0z3a1as4ddmdv1rxqvqng0sxhwaf";
      };
  
      meta = with pkgs.stdenv.lib; {
  