Task Exception Was Never Retrieved

Why This Happens

When a fire-and-forget task raises an exception, Python logs a warning because nothing is waiting for the result. This can hide bugs in your async code.

The Problem

async def risky():
    raise ValueError('error')

async def main():
    asyncio.create_task(risky())  # Exception lost!
    await asyncio.sleep(1)

The Fix

async def risky():
    raise ValueError('error')

async def main():
    task = asyncio.create_task(risky())
    try:
        await task
    except ValueError as e:
        print(f'Caught: {e}')

Step-by-Step Fix

1. 1

   Always await tasks

   Store and await task references.

2. 2

   Use asyncio.gather()

   Run and await multiple tasks together.

3. 3

   Add error callbacks

   Use task.add_done_callback() for fire-and-forget tasks.