[New-bugs-announce] [issue45924] Incorrect traceback when future's exception is raised multiple times

[Irit Katriel]

New submission from Irit Katriel <iritkatriel at gmail.com>:

Background: 
https://github.com/python/cpython/pull/29780#issuecomment-981170548
https://github.com/python/cpython/pull/29780#issuecomment-981260365

######################################################

import asyncio, traceback

async def raise_after(fut, delay):
    await asyncio.sleep(delay)
    fut.set_exception(TypeError(42))

async def main():
    loop = asyncio.get_running_loop()
    fut = loop.create_future()
    loop.create_task(
        raise_after(fut, 1))

    print('hello ...')

    for i in range(3):
        try:
            print(await fut)
        except Exception as e:
            traceback.print_exception(e)

asyncio.run(main())
######################################################

Output (traceback accumulates a frame each time):


hello ...
Traceback (most recent call last):
  File "/Users/iritkatriel/src/cpython-1/as.py", line 17, in main
    print(await fut)
          ^^^^^^^^^
TypeError: 42
Traceback (most recent call last):
  File "/Users/iritkatriel/src/cpython-1/as.py", line 17, in main
    print(await fut)
          ^^^^^^^^^
  File "/Users/iritkatriel/src/cpython-1/as.py", line 17, in main
    print(await fut)
          ^^^^^^^^^
TypeError: 42
Traceback (most recent call last):
  File "/Users/iritkatriel/src/cpython-1/as.py", line 17, in main
    print(await fut)
          ^^^^^^^^^
  File "/Users/iritkatriel/src/cpython-1/as.py", line 17, in main
    print(await fut)
          ^^^^^^^^^
  File "/Users/iritkatriel/src/cpython-1/as.py", line 17, in main
    print(await fut)
          ^^^^^^^^^
TypeError: 42

----------
components: asyncio
messages: 407265
nosy: asvetlov, gvanrossum, iritkatriel, yselivanov
priority: normal
severity: normal
status: open
title: Incorrect traceback when future's exception is raised multiple times
type: behavior
versions: Python 3.10, Python 3.11, Python 3.9

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue45924>
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