anchor.diff:  
       buildInputs = with self; [
         pkgs.libjpeg pkgs.freetype pkgs.zlib pkgs.glibcLocales
  -      pillow twitter pyfiglet requests arrow dateutil modules.readline pysocks
  +      pillow twitter pyfiglet requests2 arrow dateutil modules.readline pysocks
       ];
   
       meta = {
  
positive.code: 
    rainbowstream = buildPythonPackage rec {
      name = "rainbowstream-${version}";
      version = "1.2.7";
  
      src = pkgs.fetchurl {
        url    = "https://pypi.python.org/packages/source/r/rainbowstream/${name}.tar.gz";
        sha256 = "1jvv07w9n7ca251l92alm2yq9w82sb7lvxz6if3gc3nbqzc587rf";
      };
  
      doCheck = false;
  
negative.code:       clib=$out/${python.sitePackages}/rainbowstream/image.so
        substituteInPlace rainbowstream/c_image.py \
          --replace @CLIB@ $clib
        sed -i 's/requests.*"/requests"/' setup.py
      '';
  
      preBuild = ''
  