Access violation in Python 3.9

Hello, To be quite honest, I’m not sure whether to report it here or on comtypes GitHub page, as I’m not that familiar with either of the repositories, and importing comtypes by itself works just fine.

Expected Behavior

Importing pywinauto works without issues

Actual Behavior

Importing pywinauto causes access violation issues on Windows

Steps to Reproduce the Problem

1. Install Python 3.9
2. Install pywinauto
3. Import pywinauto in your script

Short Example of Code to Demonstrate the Problem

import faulthandler
import pywinauto
faulthandler.enable()

which then results in the following:

Windows fatal exception: code 0x80010108

Thread 0x00002358 (most recent call first):
  File "C:\Python39\lib\site-packages\comtypes\__init__.py", line 180 in _shutdown
Windows fatal exception: code 0x80010108

Thread 0x00002358 (most recent call first):
  File "C:\Python39\lib\site-packages\comtypes\__init__.py", line 180 in _shutdown

Specifications

• Pywinauto version: 0.6.8
• Python version and bitness: 3.9.5 x64
• Platform and OS: Win 10x64

[prokmi]

For the time being, I thought of a workaround of just atexit.unregister(comtypes._shutdown). How unsafe is it?

[vasily-v-ryabov]

Oh, wait! comtypes calls only atexit.register(_shutdown) while atexit.unregister(_shutdown) fixes the problem. So in fact we unregister correct handler which fails. Still not good.