anchor.diff:    };
   
     gevent = buildPythonPackage rec {
  -    name = "gevent-1.0.2";
  -    disabled = isPy3k || isPyPy;  # see https://github.com/surfly/gevent/issues/248
  +    name = "gevent-1.1rc3";
   
       src = pkgs.fetchurl {
         url = "https://pypi.python.org/packages/source/g/gevent/${name}.tar.gz";
  -      sha256 = "0cds7yvwdlqmd590i59vzxaviwxk4js6dkhnmdxb3p1xac7wmq9s";
  -    };
  -
  -    patchPhase = ''
  -      substituteInPlace libev/ev.c --replace \
  -        "ecb_inline void ecb_unreachable (void) ecb_noreturn" \
  -        "ecb_inline ecb_noreturn void ecb_unreachable (void)"
  -    '';
  -
  -    buildInputs = with self; [ pkgs.libev ];
  +      sha256 = "17g187dhr769s1rm99f2i5cjrhvmh0h3shkjdcdjciyi9ggzz56b";
  +    };
  +
  +    prePatch = ''
  +      rm -rf libev
  +    '';
  +
  +    buildInputs = [
  +      pkgs.libev
  +    ];
       propagatedBuildInputs = optionals (!isPyPy) [ self.greenlet ];
  +
  +    doCheck = false;
   
       meta = {
         description = "Coroutine-based networking library";
  
positive.code: 
    colorama = buildPythonPackage rec {
      name = "colorama-${version}";
      version = "0.3.3";
  
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/c/colorama/${name}.tar.gz";
        sha256 = "eb21f2ba718fbf357afdfdf6f641ab393901c7ca8d9f37edd0bee4806ffa269c";
      };
  
      meta = {
  
negative.code:     };
    };
  
    green = buildPythonPackage rec {
      name = "green-2.3.0";
  
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/g/green/${name}.tar.gz";
        sha256 = "1888khfl9yxb8yfxq9b48dxwplqlxx8s0l530z5j7c6bx74v08b4";
      };
  
      buildInputs = with self; [
        colorama
        mock
        termstyle
      ];
  
      meta = {
        homepage = http://pypi.python.org/pypi/green;
        platforms   = platforms.all;
      };
    };
  
    greenlet = buildPythonPackage rec {
      name = "greenlet-${version}";
      version = "0.4.9";
      disabled = isPyPy;  # builtin for pypy
  
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/g/greenlet/${name}.zip";
        sha256 = "0li2vm6ix982mmqdnqb6pgrq0jfvd0lfi5dz2rb6ap07wyig7cjq";
      };
  
      meta = {
        homepage = http://pypi.python.org/pypi/greenlet;
  