[New-bugs-announce] [issue45416] "loop argument must agree with lock" instantiating asyncio.Condition

[Simon Willison]

New submission from Simon Willison <swillison at gmail.com>:

In Python 3.10 it is not possible to instantiate an asyncio.Condition that wraps an asyncio.Lock without raising a "loop argument must agree with lock" exception.

This code raises that exception:

    asyncio.Condition(asyncio.Lock())

This worked in previous Python versions.

Note that the error only occurs if an event loop is running. Here's a simple script that replicates the problem:

    import asyncio

    # This runs without an exception:
    print(asyncio.Condition(asyncio.Lock()))

    # This does not work:
    async def example():
        print(asyncio.Condition(asyncio.Lock()))

    # This raises "ValueError: loop argument must agree with lock":
    asyncio.run(example())

----------
components: asyncio
messages: 403500
nosy: asvetlov, simonw, yselivanov
priority: normal
severity: normal
status: open
title: "loop argument must agree with lock" instantiating asyncio.Condition
versions: Python 3.10

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue45416>
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