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# In MicroPython, a non-awaited task with a pending exception will raise to

# the loop's exception handler the second time it is scheduled. This is

# because without reference counting we have no way to know when the task is

# truly "non awaited" -- i.e. we only know that it wasn't awaited in the time

# it took to be re-scheduled.

# If the task _is_ subsequently awaited, then the await should succeed without

# raising.

try:

import uasyncio as asyncio

except ImportError:

try:

import asyncio

except ImportError:

print("SKIP")

raise SystemExit

def custom_handler(loop, context):

print("exception handler", type(context["exception"]).__name__)

async def main():

loop = asyncio.get_event_loop()

loop.set_exception_handler(custom_handler)

async def task():

print("raise")

raise OSError

print("create")

t = asyncio.create_task(task())

print("sleep 1")

await asyncio.sleep(0)

print("sleep 2")

await asyncio.sleep(0)

print("await")

await t # should not raise.

asyncio.run(main())