RuntimeError: can't register atexit after shutdown

When running a simple vpython script, as I move the mouse across the screen I get a continual stream of these errors:

Task exception was never retrieved
future: <Task finished name='Task-2435' coro=<WSserver.onMessage() done, defined at C:\Users\kg604c\AppData\Roaming\Python\Python310\site-packages\vpython\no_notebook.py:181> exception=RuntimeError("can't register atexit after shutdown")>
Traceback (most recent call last):
  File "C:\Users\kg604c\AppData\Roaming\Python\Python310\site-packages\vpython\no_notebook.py", line 214, in onMessage
    await loop.run_in_executor(None, GW.handle_msg, msg)
  File "C:\Program Files\Python310\lib\asyncio\base_events.py", line 808, in run_in_executor
    executor = concurrent.futures.ThreadPoolExecutor(
  File "C:\Program Files\Python310\lib\concurrent\futures\__init__.py", line 49, in __getattr__
    from .thread import ThreadPoolExecutor as te
  File "C:\Program Files\Python310\lib\concurrent\futures\thread.py", line 37, in <module>
    threading._register_atexit(_python_exit)
  File "C:\Program Files\Python310\lib\threading.py", line 1484, in _register_atexit
    raise RuntimeError("can't register atexit after shutdown")
RuntimeError: can't register atexit after shutdown

This seems to be the same issue as mentioned in #133 however that was a few years ago. I’m unable to downgrade to an older version of python though, is it still something that hasn’t been fixed?

I’m running Python 3.10.0 and VPython 7.6.3

[BruceSherwood]

I happen to be running VPython 7.6.3 with Python 3.9.7, so I will update to 3.10 to see if I can reproduce the error. Thanks for the info.

[BruceSherwood]

I have no idea why that loop was relevant, but should you ever wish to run in jupyter notebook or jupyter lab or Web VPython I think the display will freeze (I know for sure it will freeze in Web VPython). Instead of “pass” use “rate(100)” or similar statement. It happens that of all the various instantiations of VPython, only the “no-notebook” version uses threads, which means that displays can be updated (associated with mousing, for example).