anchor.diff:    };
   
     eventlet = buildPythonPackage rec {
  -    name = "eventlet-0.17.4";
  -
  -    src = pkgs.fetchurl {
  -      url = "mirror://pypi/e/eventlet/${name}.tar.gz";
  -      sha256 = "0vam0qfm8p5jkpp2cv12r5bnpnv902ld7q074h7x5y5g9rqyj8c7";
  +    pname = "eventlet";
  +    version = "0.20.0";
  +    name = "${pname}-${version}";
  +
  +    src = fetchPypi {
  +      inherit pname version;
  +      sha256 = "15bq5ybbigxnp5xwkps53zyhlg15lmcnq3ny2dppj0r0bylcs5rf";
       };
   
       buildInputs = with self; [ nose httplib2 pyopenssl  ];
   
       doCheck = false;  # too much transient errors to bother
   
  -    propagatedBuildInputs = optionals (!isPyPy) [ self.greenlet ];
  +    propagatedBuildInputs = optionals (!isPyPy) [ self.greenlet ] ++
  +      (with self; [ enum-compat ]) ;
   
       meta = {
         homepage = http://pypi.python.org/pypi/eventlet/;
  
positive.code:   olefile = callPackage ../development/python-modules/olefile { };
  
    oslo-log = buildPythonPackage rec {
      name = "oslo.log-${version}";
      version = "1.12.1";
  
      src = pkgs.fetchurl {
        url = "mirror://pypi/o/oslo.log/${name}.tar.gz";
        sha256 = "10x596r19zjla5n1bf04j5vncx0c9gpc5wc2jlmgjbl3cyx3vgsv";
      };
  
      propagatedBuildInputs = with self; [
        pbr Babel six iso8601 debtcollector
        oslo-utils oslo-i18n oslo-config oslo-serialization oslo-context
      ] ++ stdenv.lib.optional stdenv.isLinux pyinotify;
      buildInputs = with self; [ oslotest oslosphinx ];
  
negative.code: 
  
    oslo-utils = buildPythonPackage rec {
      pname = "oslo.utils";
      version = "3.29.0";
      name = "${pname}-${version}";
  
      src = fetchPypi {
        inherit pname version;
        sha256 = "0l90ijw96czjd6z8bw88983rsnq5753iw86rhk1wi064w4rs19ig";
      };
  
      propagatedBuildInputs = with self; [ pbr Babel six iso8601 pytz netaddr netifaces
  