mayavi2 does not start - traceback traits.trait_errors.TraitError: Each element of the 'groups' trait of a Menu instance must be a Group or None, but a value of 'OpenGroup' <class 'str'> was specified.

[dpinte]

$ mayavi2
ERROR|2022-10-12 16:29:39,689|getting extensions from Plugin(id='envisage.ui.workbench', name='Workbench'), trait <my_action_sets>
Traceback (most recent call last):
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/plugin.py", line 326, in _get_extensions_from_trait
    extensions = getattr(self, trait_name)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/ui/workbench/workbench_plugin.py", line 185, in _my_action_sets_default
    from .default_action_set import DefaultActionSet
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/ui/workbench/default_action_set.py", line 21, in <module>
    class DefaultActionSet(ActionSet):
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/ui/workbench/default_action_set.py", line 25, in DefaultActionSet
    Menu(
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/trait_types.py", line 2695, in validate
    return TraitListObject(self, object, name, value)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/trait_list_object.py", line 584, in __init__
    super().__init__(
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/trait_list_object.py", line 213, in __init__
    super().__init__(self.item_validator(item) for item in iterable)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/trait_list_object.py", line 213, in <genexpr>
    super().__init__(self.item_validator(item) for item in iterable)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/trait_list_object.py", line 867, in _item_validator
    return trait_validator(object, self.name, value)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/base_trait_handler.py", line 74, in error
    raise TraitError(
traits.trait_errors.TraitError: Each element of the 'groups' trait of a Menu instance must be a Group or None, but a value of 'OpenGroup' <class 'str'> was specified.
Traceback (most recent call last):
  File "/Users/dpinte/.edm/envs/test/bin/mayavi2", line 10, in <module>
    sys.exit(main())
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/mayavi/scripts/mayavi2.py", line 600, in main
    mayavi.main(sys.argv[1:])
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/mayavi/plugins/app.py", line 197, in main
    app.run()
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/mayavi/plugins/mayavi_workbench_application.py", line 81, in run
    window.open()
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/pyface/workbench/workbench_window.py", line 159, in open
    self._create()
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/pyface/ui/qt4/application_window.py", line 138, in _create
    self._create_trim_widgets(self.control)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/pyface/i_application_window.py", line 155, in _create_trim_widgets
    self._create_menu_bar(parent)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/pyface/ui/qt4/application_window.py", line 79, in _create_menu_bar
    if self.menu_bar_manager is not None:
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/ui/workbench/workbench_window.py", line 106, in _menu_bar_manager_default
    return self._action_manager_builder.create_menu_bar_manager("MenuBar")
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/ui/workbench/workbench_window.py", line 224, in __action_manager_builder_default
    window=self, action_sets=self.action_sets
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/ui/workbench/workbench_window.py", line 168, in _action_sets_default
    return [factory(window=self) for factory in self._action_sets]
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/extension_point.py", line 122, in get
    extensions = extension_registry.get_extensions(self.id)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/application.py", line 203, in get_extensions
    return self.extension_registry.get_extensions(extension_point_id)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/extension_registry.py", line 110, in get_extensions
    return self._get_extensions(extension_point_id)[:]
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/provider_extension_registry.py", line 99, in _get_extensions
    extensions = self._initialize_extensions(extension_point_id)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/provider_extension_registry.py", line 279, in _initialize_extensions
    extensions.append(provider.get_extensions(extension_point_id)[:])
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/plugin.py", line 137, in get_extensions
    extensions = self._get_extensions_from_trait(trait_names[0])
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/plugin.py", line 326, in _get_extensions_from_trait
    extensions = getattr(self, trait_name)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/ui/workbench/workbench_plugin.py", line 185, in _my_action_sets_default
    from .default_action_set import DefaultActionSet
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/ui/workbench/default_action_set.py", line 21, in <module>
    class DefaultActionSet(ActionSet):
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/envisage/ui/workbench/default_action_set.py", line 25, in DefaultActionSet
    Menu(
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/trait_types.py", line 2695, in validate
    return TraitListObject(self, object, name, value)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/trait_list_object.py", line 584, in __init__
    super().__init__(
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/trait_list_object.py", line 213, in __init__
    super().__init__(self.item_validator(item) for item in iterable)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/trait_list_object.py", line 213, in <genexpr>
    super().__init__(self.item_validator(item) for item in iterable)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/trait_list_object.py", line 867, in _item_validator
    return trait_validator(object, self.name, value)
  File "/Users/dpinte/.edm/envs/test/lib/python3.8/site-packages/traits/base_trait_handler.py", line 74, in error
    raise TraitError(
traits.trait_errors.TraitError: Each element of the 'groups' trait of a Menu instance must be a Group or None, but a value of 'OpenGroup' <class 'str'> was specified.

[dpinte]

The bug seems to be an issue due to the traits validation for https://github.com/enthought/envisage/blob/main/envisage/ui/workbench/default_action_set.py#L28 .

[dpinte]

The traits validation seemed to be the culprit. Testing with traits 6.3.2 works fine. The issue starts with 6.4.1 or the combination of other ETS dependencies coming with that version

[corranwebster]

~The trait error here is misleading. The problem is that the groups trait of a Menu is a read-only property: https://github.com/enthought/pyface/blob/608e153cb0f067223de82df608f8067f1d94a6a2/pyface/action/action_manager.py#L47-L48 Instead groups are intended to be passed through as *args to the Menu().~

~So the code here: https://github.com/enthought/envisage/blob/ebca726572a4ec565c82cc4091ec1f2d3c96a76c/envisage/ui/workbench/default_action_set.py#L25-L29 should instead look like:~

        Menu(
            "OpenGroup", "SaveGroup", "ImportGroup", "ExitGroup"
            name="&File",
            path="MenuBar",
        ),

~and so on for the other menus.~

~If this code worked in the past, it was purely by accident!~

Edit: Sorry, this is a different Menu object, from here: https://github.com/enthought/envisage/blob/ebca726572a4ec565c82cc4091ec1f2d3c96a76c/envisage/ui/action/menu.py#L50

The change in traits which is responsible is this one: https://github.com/enthought/traits/pull/1625 (see https://github.com/enthought/traits/issues/1619 for the issue it fixed).

I'm not quite sure how it worked previously, as traits typically don't validate default values, so I'm not sure if it is a bug or not. In any case, a work around is to use Group("OpenGroup") and so forth.

[prabhuramachandran]

I tried your workaround and the syntax that works is Group(id="OpenGroup") and this fixes the issue. Should I send a PR to envisage for this?

[prabhuramachandran]

I just submitted a PR to envisage that addresses this. https://github.com/enthought/envisage/pull/485

[PaoloSuin]

I am still having an issue. Downgrading traits to 6.3.1 or applying the fix in https://github.com/enthought/traits/issues/1619 gives another error:

mayavi2
      QSocketNotifier: Can only be used with threads started with QThread
      multiple 'tvtk.toolkits' plugins found for toolkit 'qt4': tvtk.pyface.ui.qt4.init, tvtk.pyface.ui.qt4.init
      X Error of failed request:  BadWindow (invalid Window parameter)
            Major opcode of failed request:  3 (X_GetWindowAttributes)
            Resource id in failed request:  0x5
            Serial number of failed request:  7
            Current serial number in output stream:  8

Anyway I am not sure where to apply the fix Group(id="OpenGroup")

Any help?