Segfault with `asyncio.base_events.BaseEventLoop` when passed a small float to `set_debug`.

[devdanzin]

Crash report

What happened?

It's possible to segfault the interpreter by passing a small float as the enabled parameter of asyncio.base_events.BaseEventLoop.set_debug():

import asyncio.base_events

obj = asyncio.base_events.BaseEventLoop()
obj.set_debug(0.0005)
obj._run_forever_setup()

Found using fusil by @vstinner.

CPython versions tested on:

3.13, 3.14, CPython main branch

Operating systems tested on:

Linux

Output from running 'python -VV' on the command line:

Python 3.14.0a1+ experimental free-threading build (heads/main-dirty:54c63a32d0, Nov 8 2024, 20:16:36) [GCC 11.4.0]

Linked PRs

• gh-126881: store debug flag for event loops as a boolean #126901
• gh-126881: fix finalization of dtoa state #126904
• [3.13] gh-126881: fix finalization of dtoa state (GH-126904) #127395

[picnixz]

I'm assuming that this only happens on the free-threaded build, or?

[devdanzin]

No, it segfaults on normal build too, sorry for not mentioning it.

[picnixz]

I'll have a look at this one.