anchor.diff:  
   
     djblets = buildPythonPackage rec {
  -    name = "Djblets-0.6.23";
  +    name = "Djblets-0.6.28";
   
       src = fetchurl {
         url = "http://downloads.reviewboard.org/releases/Djblets/0.6/${name}.tar.gz";
  -      sha256 = "1d8vg5a9q2ldnbxqap1893lqb66jwcsli2brbjx7mcnqrzcz449x";
  -    };
  -
  -    propagatedBuildInputs = [ pil django_1_3 ];
  +      sha256 = "11fsi911cqkjgv9j7646ljc2fgxsdfyq44kzmv01xhysm50fn6xx";
  +    };
  +
  +    propagatedBuildInputs = [ pil django_1_3 feedparser ];
   
       meta = {
         description = "A collection of useful extensions for Django";
  
positive.code: 
  
    django_1_3 = buildPythonPackage rec {
      name = "Django-1.3.3";
  
      src = fetchurl {
        url = "http://www.djangoproject.com/m/releases/1.3/${name}.tar.gz";
        sha256 = "0snlrcvk92qj1v0n9dpycn6sw56w4zns4mpc30837q6yi7ylrx4f";
      };
  
      # error: invalid command 'test'
  
negative.code: 
  
    reviewboard = buildPythonPackage rec {
      name = "ReviewBoard-1.6.16";
  
      src = fetchurl {
        url = "http://downloads.reviewboard.org/releases/ReviewBoard/1.6/${name}.tar.gz";
        sha256 = "0vg3ypm57m43bscv8vswjdllv3d2j8lxqwwvpd65cl7jd1in0yr1";
      };
  
      propagatedBuildInputs =
        [ recaptcha_client pytz memcached dateutil_1_5 paramiko flup pygments
          djblets django_1_3 django_evolution pycrypto python.modules.sqlite3
          pysvn pil psycopg2
        ];
  