python3Packages.eventlet: loosen dnspython bounds, refactor

pkgs/development/python-modules/eventlet/default.nix

@@ -19,11 +19,20 @@ buildPythonPackage rec {
     sha256 = "4f4a43366b4cbd4a3f2f231816e5c3dae8ab316df9b7da11f0525e2800559f33";
   };
 
+  propagatedBuildInputs = [ dnspython greenlet monotonic six ]
+    ++ lib.optional (pythonOlder "3.4") enum34;
+
+  prePatch = ''
+    substituteInPlace setup.py \
+      --replace "dnspython >= 1.15.0, < 2.0.0" "dnspython"
+  '';
+
   checkInputs = [ nose ];
 
   doCheck = false;  # too much transient errors to bother
 
-  propagatedBuildInputs = [ dnspython greenlet monotonic six ] ++ lib.optional (pythonOlder "3.4") enum34;
+  # unfortunately, it needs /etc/protocol to be present to not fail
+  #pythonImportsCheck = [ "eventlet" ];
 
   meta = with lib; {
     homepage = "https://pypi.python.org/pypi/eventlet/";