sockets and asyncio on Windows depend on SYSTEMROOT env var

Bug report

Bug description:

os.environ.clear() # THIS WAS THE CAUSE!!!
import asyncio

This causes the following:

Traceback (most recent call last):
  File "c:\Users\user\Documents\Development\main\main.py", line 3, in <module>
    import asyncio
  File "C:\Program Files\Python311\Lib\asyncio\__init__.py", line 42, in <module>
    from .windows_events import *
  File "C:\Program Files\Python311\Lib\asyncio\windows_events.py", line 8, in <module>
    import _overlapped
OSError: [WinError 10106] The requested service provider could not be loaded or initialized

It took me a whole day to figure out that os.environ.clear() causes this bug to occur. I'm not sure if this is supposed to occur, I just thought I would post this in case other people are struggling with this.

CPython versions tested on:

3.8, 3.9, 3.10, 3.11

Operating systems tested on:

Windows

Linked PRs

• gh-134363
• gh-134435

首先檢查透過 asyncio/init.py 和 asyncio/windows_events.py 的已回報匯入路徑，然後查看關聯的 PR gh-134363 和 gh-134435。在匯入 asyncio 之前使用 os.environ.clear()，在 Windows 上重現該故障，並利用現有討論確定預期行為和完成標準。