Qt module usage in plugins cause conflict with USD (Tf module) loading halting iniitialization.

[kwokcb]

Issue

If you do the install:

pip install QuiltiX
pip install git+https://github.com/PrismPipeline/OpenUSD_build.git@25.05.01-win-mtlx-1.39.3

then try and run tests or load in a plugin you get this error (e.g for first test)

======================================================================
ERROR: test_node_creation (unittest.loader._FailedTest.test_node_creation)
----------------------------------------------------------------------
ImportError: Failed to import test module: test_node_creation
Traceback (most recent call last):
  File "C:\Users\home\AppData\Local\Programs\Python\Python311\Lib\unittest\loader.py", line 407, in _find_test_path
    module = self._get_module_from_name(name)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\home\AppData\Local\Programs\Python\Python311\Lib\unittest\loader.py", line 350, in _get_module_from_name
    __import__(name)
  File "D:\Work\materialx\QuiltiX\tests\test_node_creation.py", line 1, in <module>
    from examples.create_all_available_nodes import create_all_available_nodes
  File "D:\Work\materialx\QuiltiX\examples\create_all_available_nodes.py", line 1, in <module>
    from tests import helpers
  File "D:\Work\materialx\QuiltiX\tests\helpers.py", line 7, in <module>
    from QuiltiX import quiltix
  File "D:\Work\materialx\QuiltiX\venv\Lib\site-packages\QuiltiX\quiltix.py", line 25, in <module>
    from pxr import Usd, UsdShade
  File "D:\Work\materialx\QuiltiX\venv\Lib\site-packages\pxr\Usd\__init__.py", line 7, in <module>
    from pxr import Tf
  File "D:\Work\materialx\QuiltiX\venv\Lib\site-packages\pxr\Tf\__init__.py", line 161, in <module>
    PreparePythonModule()
  File "D:\Work\materialx\QuiltiX\venv\Lib\site-packages\pxr\Tf\__init__.py", line 86, in PreparePythonModule
    module = importlib.import_module(
             ^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\home\AppData\Local\Programs\Python\Python311\Lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ImportError: DLL load failed while importing _tf: A dynamic link library (DLL) initialization routine failed.

This is the installed packages in a venv:

Package                  Version
------------------------ -------
MaterialX                1.39.3
NodeGraphQt_QuiltiX_fork 0.7.0
OpenUSD_build            1.0
packaging                25.0
pip                      25.1.1
pluggy                   1.6.0
PyOpenGL                 3.1.9
PyOpenGL-accelerate      3.1.9
PySide6                  6.5.3
PySide6-Addons           6.5.3
PySide6-Essentials       6.5.3
QtPy                     2.4.3
QuiltiX                  0.8.0
setuptools               79.0.1
shiboken6                6.5.3
wheel                    0.45.1

Running with Python 3.11.0

[kwokcb]

Cross reference with #102 which has the same symptom.

[manuelkoester]

Thanks for reporting! I can reproduce this on my end.
Hmmm, this has to be related to the new OpenUSD build, however I can't see anything that would cause this. I'll try to investigate soon

[manuelkoester]

After debugging it for a bit I'm more puzzled than before. I was able debug the tests with pdb and inspect the environment variables and everything seems in order.
I also checked if the .dlls match and have their required depenencies calling https://lucasg.github.io/Dependencies/ from that Exception breakpoint, but everything looks a-okay to me.

[manuelkoester]

Had another look and the plugin execution runs fine for me, only the tests fail. I think it has something to do with pytest + qtbot, but haven't had enough time to find the root issue yet.

This is materialxjson running:

import os
os.environ["QUILTIX_PLUGIN_PATHS"] = "sample_plugins/materialxjson"

from QuiltiX import quiltix
quiltix.launch()

[manuelkoester]

Thanks to a test from @RichardFrangenberg this seems to be gone with later PySide6 versions like 6.8

We are trying to stay within the vfx reference platform for now however (which is PySide6~=6.5.0 for now). Will mark as upstream issue.

Separately the tests have not been maintained however and are basically all failing (but not due to this :D ). Will open a separate issue

Do you see any issues outside of tests @kwokcb

[kwokcb]

Thanks for looking at this. I think that for some reason that importing Qt is causing this error to occur.

There the new information:

1. Install the latest version of materialxjson : Should be 1.39.3

2. Set the QUILTIX_PLUGIN_PATHS=./sample_plugins/materialxjson

3. It will produce the error

4. If you comment out these lines (and code that adds the UI) in the plugin.py sample

#from qtpy import QtCore  # type: ignore
#from qtpy.QtWidgets import (  # type: ignore
#    QAction,
#    QTextEdit,
#)

then it loads?

All of my plugins naturally need Qt to add menu items so they are all unloadable currently.

I'm on Windows 11 if that makes any difference. I don't have Qt installed anywhere.

Any ideas @manuelkoester ?

[kwokcb]

This is the minimum plugin which will cause this error:

import logging

logger = logging.getLogger(name)

from QuiltiX import qx_plugin, constants

try:
from qtpy import QtCore # type: ignore
#from qtpy.QtWidgets import ( # type: ignore
# QTextEdit
#)
pass
except ImportError as e:
logger.error("Error trying to import qtpy: %s", e)

@qx_plugin.hookimpl
def after_ui_init(editor: "quiltix.QuiltiXWindow"):
logger.info("Initializing plugin...")

def plugin_name() -> str:
logger.info("Returning plugin name")
return "QX Plugin"

def is_valid() -> bool:
return True

[kwokcb]

I've put up a PR (#109) with a workaround. I'm not sure if it's a good fix but it's a workaround for now.