python3Packages.clize: relax docutils constraint, set up extras-require

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

@@ -1,12 +1,18 @@
 { lib
 , buildPythonPackage
 , fetchPypi
-, python-dateutil
+
+# propagtes
 , sigtools
 , six
 , attrs
 , od
 , docutils
+
+# extras: datetime
+, python-dateutil
+
+# tests
 , pygments
 , unittest2
 , pytestCheckHook
@@ -21,6 +27,25 @@ buildPythonPackage rec {
     sha256 = "3177a028e4169d8865c79af82bdd441b24311d4bd9c0ae8803641882d340a51d";
   };
 
+  postPatch = ''
+    substituteInPlace setup.py \
+      --replace "docutils ~= 0.17.0" "docutils"
+  '';
+
+  propagatedBuildInputs = [
+    attrs
+    docutils
+    od
+    sigtools
+    six
+  ];
+
+  passthru.extras-require = {
+    datetime = [
+      python-dateutil
+    ];
+  };
+
   # repeated_test no longer exists in nixpkgs
   # also see: https://github.com/epsy/clize/issues/74
   doCheck = false;
@@ -31,14 +56,6 @@ buildPythonPackage rec {
     unittest2
   ];
 
-  propagatedBuildInputs = [
-    attrs
-    docutils
-    od
-    sigtools
-    six
-  ];
-
   pythonImportsCheck = [ "clize" ];
 
   meta = with lib; {