gistfile1.txt

❯ python t.py
Traceback (most recent call last):
  File "t.py", line 7, in tf
    await asyncio.wait_for(con.wait(), 10)
  File "/Users/hynek/.pyenv/versions/3.8.1/lib/python3.8/asyncio/tasks.py", line 476, in wait_for
    await waiter
asyncio.exceptions.CancelledError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "t.py", line 23, in <module>
    asyncio.run(f())
  File "/Users/hynek/.pyenv/versions/3.8.1/lib/python3.8/asyncio/runners.py", line 43, in run
    return loop.run_until_complete(main)
  File "/Users/hynek/.pyenv/versions/3.8.1/lib/python3.8/asyncio/base_events.py", line 612, in run_until_complete
    return future.result()
  File "t.py", line 19, in f
    await t
  File "t.py", line 7, in tf
    await asyncio.wait_for(con.wait(), 10)
  File "/Users/hynek/.pyenv/versions/3.8.1/lib/python3.8/asyncio/locks.py", line 103, in __aexit__
    self.release()
  File "/Users/hynek/.pyenv/versions/3.8.1/lib/python3.8/asyncio/locks.py", line 229, in release
    raise RuntimeError('Lock is not acquired.')
RuntimeError: Lock is not acquired.

t.py

import asyncio


async def tf(con):
    async with con:
        await asyncio.wait_for(con.wait(), 10)


async def f():
    con = asyncio.Condition()

    t = asyncio.create_task(tf(con))
    await asyncio.sleep(1)
    t.cancel()

    async with con:
        con.notify_all()
    await t


asyncio.run(f())