python3Packages.qtpy: fix build

Needed to propagate packaging and took some time to look at the tests.

The tests need pyqt5 with certain features, but pyqt5 takes roughly an
hour to build so after two tries I wasn't going to spend more time and
decided to keep the test disabled with updated hints.

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

@@ -1,21 +1,49 @@
-{ lib, buildPythonPackage, fetchPypi, pyside, pytest }:
+{ lib
+, buildPythonPackage
+, fetchPypi
+, pythonOlder
+
+# propagates
+, packaging
+
+# tests
+, pyqt5
+, pyside
+, pytestCheckHook
+}:
 
 buildPythonPackage rec {
   pname = "QtPy";
   version = "2.0.0";
+  format = "setuptools";
+
+  disabled = pythonOlder "3.6";
 
   src = fetchPypi {
     inherit pname version;
     sha256 = "777e333df4d711b2ec9743117ab319dadfbd743a5a0eee35923855ca3d35cd9d";
   };
 
-  # no concrete propagatedBuildInputs as multiple backends are supposed
-  checkInputs = [ pyside pytest ];
+  propagatedBuildInputs = [
+    packaging
+  ];
 
-  doCheck = false; # require X
-  checkPhase = ''
-    py.test qtpy/tests
-  '';
+  doCheck = false; # ModuleNotFoundError: No module named 'PyQt5.QtConnectivity'
+  checkInputs = [
+    pyside
+    (pyqt5.override {
+      withConnectivity = true;
+      withMultimedia = true;
+      withWebKit = true;
+      withWebSockets = true;
+    })
+    pytestCheckHook
+  ];
+
+  disabledTestPaths = [
+    # Fatal error in python on x86_64
+    "qtpy/tests/test_uic.py"
+  ];
 
   meta = with lib; {
     description = "Abstraction layer for PyQt5/PyQt4/PySide2/PySide";