anchor.diff:  { stdenv
   , buildPythonPackage
  -, fetchgit
  -, fetchTritonPatch
  -, fetchurl
  +, fetchFromGitHub
  +,  fetchurl
   , gettext
   , intltool
   , isPy3
  
positive.code: let
    inherit (lib)
      makeSearchPath
      optionals
      optionalString;
  
    sources = {
      "stable" = {
        version = "1.3.15";
        sha256 = "a96405140e3cbc569e6e056165e289a5e9ec66e036c327f3912c73d049ccf92c";
      };
      "head" = {
        fetchzipversion = 6;
  
negative.code:   src =
      if channel != "head" then
        fetchurl {
          url = "http://download.deluge-torrent.org/source/2.0/"
            + "deluge-${source.version}.tar.xz";
          inherit (source) sha256;
        }
      else
        fetchFromGitHub {
          version = source.fetchzipversion;
          owner = "deluge-torrent";
          repo = "deluge";
          inherit (source) rev sha256;
        };
  
  