Bug report

Bug description:

-X lazy_imports, -X thread_inherit_context, and -X context_aware_warnings are not inherited via subprocess._args_from_interpreter_flags() so multiprocessing spawned child processes do not inherit these -X settings unless the user happens to be using the dangerous non-default "fork" start method.

We should consider this for every -X option added. In general the answer should be "yes". There's a list in Lib/subprocess.py to update. (could we automate this by making the list an opt-out instead of a remember-when-adding-a-feature-to-opt-in list?)

Linked PRs

• gh-146004: propagate all -X options to multiprocessing child processes #146005
• [3.14] gh-146004: propagate all -X options to multiprocessing child processes (GH-146005) #146552
• gh-146004: fix test_args_from_interpreter_flags #146580
• [3.14] gh-146004: fix test_args_from_interpreter_flags on windows (GH-146580) #146585