`asyncio.wait(timeout=5)` returns early (~1.5 ms) on macOS with Python 3.14.x free-threaded

[ayjayt]

Bug report

Bug description:

Unfortunately, I'm running these tests in github's CI, obviously not the most ergonomic environment and I can't provide more tests right now.

I have attached the logs and the code to demonstrate the error.

PS: it happens very consistently but once of the 20 tests, it did not. It does NOT occur on 3.14 or lower- nor any of these versions on linux nor windows.

Here is the code:

 _logger.debug(f"Starting wait: timeout={timeout}")
# Race between the two methods: first one to complete wins
done, pending = await asyncio.wait(
    [
        load_future,
        js_ready_future,
    ],
    return_when=asyncio.FIRST_COMPLETED,
    timeout=timeout,
)
_logger.debug(f"Finish wait, is done? {bool(done)}")

for task in pending:
    _logger.debug(f"Cancelling: {task}")
    task.cancel()

if not done:
    _logger.debug("Timeout waiting for js or event")
    raise asyncio.TimeoutError(  # noqa: TRY301
        "Page load timeout",
    )
else:
    _logger.debug(f"Task which finished: {done}")

here's the logs:

Build and Test (macos-latest, 3.14t)	Test	2025-11-26T20:48:35.2630790Z DEBUG    choreographer.protocol.devtools_async_helpers:devtools_async_helpers.py:90 Starting wait: timeout=5.0
Build and Test (macos-latest, 3.14t)	Test	2025-11-26T20:48:35.2644080Z DEBUG    choreographer.protocol.devtools_async_helpers:devtools_async_helpers.py:100 Finish wait, is done? False
Build and Test (macos-latest, 3.14t)	Test	2025-11-26T20:48:35.2644660Z DEBUG    choreographer.protocol.devtools_async_helpers:devtools_async_helpers.py:103 Cancelling: <Future pending>
Build and Test (macos-latest, 3.14t)	Test	2025-11-26T20:48:35.2645810Z DEBUG    choreographer.protocol.devtools_async_helpers:devtools_async_helpers.py:103 Cancelling: <Task pending name='Task-42' coro=<_check_document_ready() running at /Users/runner/work/choreographer/choreographer/.venv/lib/python3.14t/site-packages/choreographer/protocol/devtools_async_helpers.py:30> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Build and Test (macos-latest, 3.14t)	Test	2025-11-26T20:48:35.2647130Z DEBUG    choreographer.protocol.devtools_async_helpers:devtools_async_helpers.py:107 Timeout waiting for js or event

1. We set timeout to 5 seconds
2. We exit asyncio.wait() after 1.5ms
3. Both futures in asyncio.wait() show to be still pending after exiting wait(), therefore they did not provoke the exit.

CPython versions tested on:

3.14

Operating systems tested on:

macOS

[StanFromIreland]

Can you please provide a self-contained example?

[ayjayt]

Thanks @StanFromIreland - I've sent a script to be tested by some colleagues who have macs, I will reply here with the results if/when I get them. I can't guarantee that I'll be able to reproduce it in a less-constrained environment.

I'm pushing the limit on my github minutes, it seems.

[ayjayt]

I was not able to reproduce a simple example.

I will investigate further (assign me?), and I'm leaving the failing commit here to give myself a reference point:

plotly/choreographer#283
https://github.com/plotly/choreographer/actions/runs/19807518288/job/56744065193
https://github.com/plotly/choreographer/actions/runs/19715563004

• Reproduce and re-verify error again
• Scale testing down to just this
• Run test in script out of pytest to see if its pytest or myptest module interference
• Get some kind of ultra high asyncio debugging up (can I print internals?)
• Try to reproduce with home-build of python

[kumaraditya303]

Can you provide a reproducer for it?

[ayjayt]

Hi @kumaraditya303, sorry I've been a bit behind for a month on everything, holidays + responsibility shift at work.

This topic is coming up relatively soon, like within 30 days, and I'll re-investigate it.

I was not able to provide a simple reproducer for it, but I think we're going to use at as an excuse to learn about debugging cpython if you have any tips.