anchor.diff:  
     mechanize = buildPythonPackage (rec {
       name = "mechanize-0.1.11";
  +    disabled = isPy3k;
   
       src = fetchurl {
         url = "http://wwwsearch.sourceforge.net/mechanize/src/${name}.tar.gz";
  
positive.code:   reportlab =
     let freetype = overrideDerivation pkgs.freetype (args: { configureFlags = "--enable-static --enable-shared"; });
     in buildPythonPackage rec {
      name = "reportlab-2.5";
  
      src = fetchurl {
        url = "http://pypi.python.org/packages/source/r/reportlab/${name}.tar.gz";
        md5 = "cdf8b87a6cf1501de1b0a8d341a217d3";
      };
  
      buildInputs = [freetype];
  
negative.code: 
    flexget = buildPythonPackage rec {
      name = "FlexGet-1.2.161";
      disabled = isPy3k;
  
      src = fetchurl {
        url = "https://pypi.python.org/packages/source/F/FlexGet/${name}.tar.gz";
  