anchor.diff:        sha256 = "1q35kgz151rr99240jq55rs39y741m8shh9yihl3x95rkjxchji4";
       };
   
  -    propagatedBuildInputs = with self; [ cython pkgs.openssl dns dateutil xcaplib msrplib lxml ];
  +    propagatedBuildInputs = with self; [ cython pkgs.openssl dns dateutil xcaplib msrplib lxml python-otr ];
       buildInputs = with pkgs; [ alsaLib ffmpeg libv4l pkgconfig sqlite libvpx ];
     };
   
  
positive.code:   gnutls = buildPythonPackage rec {
      name = "python-gnutls";
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/p/python-gnutls/python-gnutls-2.0.1.tar.gz";
        sha256 = "d8fb368c6a4dd58bc6cd5e61d4a12d119c4506fd344a371b3429b3ac2623b9ac";
      };
  
      propagatedBuildInputs = with self; [ pkgs.gnutls ];
  
negative.code:     };
    };
  
    python-otr = buildPythonPackage rec {
      name = "${pname}-${version}";
      pname = "python-otr";
      version = "1.2.0";
  
      disabled = isPy3k;
  
      src = pkgs.fetchFromGitHub {
        owner = "AGProjects";
        repo = pname;
        rev = "release-" + version;
        sha256 = "0p3b1n8jlxwd65gbk2k5007fkhdyjwcvr4982s42hncivxvabzzy";
      };
  
      propagatedBuildInputs = with self; [ zope_interface cryptography application gmpy2 ];
  
      meta = {
        description = "A pure python implementation of OTR";
        homepage = https://github.com/AGProjects/otr;
        license = licenses.lgpl21Plus;
        platforms = platforms.linux;
        maintainers = with maintainers; [ edwtjo ];
      };
    };
  
    ply = buildPythonPackage (rec {
      name = "ply-3.8";
  
  