anchor.diff:  
     pep8 = buildPythonPackage rec {
       name = "pep8-${version}";
  -    version = "1.4.5";
  +    version = "1.4.6";
   
       src = fetchurl {
         url = "http://pypi.python.org/packages/source/p/pep8/${name}.tar.gz";
  -      md5 = "055dbd22ac5669232fdba752612e9686";
  +      md5 = "a03bb494859e87b42601b61b1b043a0c";
       };
   
       #======================================================================
  
positive.code: 
  
    mccabe = buildPythonPackage (rec {
      name = "mccabe-0.2";
  
      src = fetchurl {
        url = "http://pypi.python.org/packages/source/m/mccabe/${name}.tar.gz";
        md5 = "c1012c7c24081471f45aab864d4e3805";
      };
  
      buildInputs = [ ];
  
negative.code:   };
  
    pyflakes = buildPythonPackage rec {
      name = "pyflakes-0.7.3";
  
      src = fetchurl {
        url = "http://pypi.python.org/packages/source/p/pyflakes/${name}.tar.gz";
        md5 = "ec94ac11cb110e6e72cca23c104b66b1";
      };
  
      buildInputs = [ unittest2 ];
  