Propagate errors to main asyncio loop

[recycletechno]

I have a program which runs asyncio loop, starts tasks and at the end runs AsyncIOScheduler jobs with scheduler.add_job(). I set an exception handler for asyncio loop which sends info about error to my email/messenger and stops the loop gracefully.

# Exception handler
loop = asyncio.get_event_loop()
loop.set_exception_handler(handle_exception)

But if I catch any exception in one of AsyncIOScheduler tasks it just prints the error message in logs and does not call handle_exception and does not stop.

How can I propagate AsyncIOScheduler to the main asyncio loop and run handle_exception on any error in AsyncIOScheduler?

For example this job will print the error and wont stop loop:

async def test_sched_error():
    await asyncio.sleep(1)
    assert 1 == 2, "Assert error"

scheduler.add_job(test_sched_error, trigger="cron", second="*/5")

And lines in logs:

--2023-09-21 13:12:16,033 [ERROR] [run_coroutine_job] Job "T.test_sched_error (trigger: cron[second='*/5'], next run at: 2023-09-21 13:12:20)" raised an exception
Traceback (most recent call last):
  File "C:\Users\user\venv\lib\site-packages\apscheduler\executors\base_py3.py", line 30, in run_coroutine_job
    retval = await job.func(*job.args, **job.kwargs)
  File "C:\Users\user\src\t_class.py", line 1207, in test_sched_error
    assert 1 == 2, "Assert error"
AssertionError: Assert error

[agronholm]

What you can do is add an event listener to the scheduler to react to job errors, and have that set the exception on a future that your application awaits on:

import asyncio

from apscheduler.events import EVENT_JOB_ERROR
from apscheduler.schedulers.asyncio import AsyncIOScheduler
from apscheduler.triggers.date import DateTrigger

def raise_error():
    raise RuntimeError

async def main():
    future = asyncio.get_running_loop().create_future()
    scheduler = AsyncIOScheduler()
    scheduler.add_listener(lambda event: future.set_exception(event.exception), EVENT_JOB_ERROR)
    scheduler.add_job(raise_error, DateTrigger())
    scheduler.start()
    await future

asyncio.run(main())

[recycletechno]

Thank you! add_listener with EVENT_JOB_ERROR is what I need