Documentation for os.environ should say that os.environ caching behavior is undefined if other threads are setting environment values

Documentation

It says here:

This mapping is captured the first time the os module is imported, typically during Python startup as part of processing site.py. Changes to the environment made after this time are not reflected in os.environ, except for changes made by modifying os.environ directly.

It should mention the caveat that such cashing would cause undefined behavior or/and crashes when other threads would be setting environment values. This would be true at least on Linux and FreeBSD.

The same should be mentioned in the documentation of the function that initializes the Python interpreter and caches environment.

These functions are not thread-safe.

Linked PRs

• gh-152979

查看 issue 中連結的 os.environ 文件，以及會快取環境的直譯器初始化函式文件。將所要求的執行緒安全注意事項與連結的 PR gh-152979 進行比較。當兩個相關的文件區域都準確描述其他執行緒修改環境值時的行為時，即表示完成。