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Created on 2020-12-19 08:09 by lilydjwg, last changed 2022-04-11 14:59 by admin. This issue is now closed.
| Messages (4) | |||
|---|---|---|---|
| msg383364 - (view) | Author: lilydjwg (lilydjwg) * | Date: 2020-12-19 08:09 | |
import asyncio
async def crash(key):
raise Exception('crash!')
async def wait(fu):
await fu
async def main():
crasher = asyncio.create_task(crash(()))
fs = [wait(crasher) for _ in range(10)]
for fu in asyncio.as_completed(fs):
try:
await fu
except Exception:
import traceback
traceback.print_exc()
if __name__ == '__main__':
asyncio.run(main())
This code will give a very long traceback 10 times. I expect it to be short.
I'm caching the result of an async function like this:
async def get(
self,
key: Hashable,
func: Callable[[Hashable], Coroutine[Any, Any, Any]],
) -> Any:
async with self.lock:
cached = self.cache.get(key)
if cached is None:
coro = func(key)
fu = asyncio.create_task(coro)
self.cache[key] = fu
if asyncio.isfuture(cached): # pending
return await cached # type: ignore
elif cached is not None: # cached
return cached
else: # not cached
r = await fu
self.cache[key] = r
return r
It works fine, except that when there is an exception the traceback is very long.
|
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| msg383637 - (view) | Author: Andrew Svetlov (asvetlov) *  |
Date: 2020-12-23 10:40 | |
The traceback contains frames from asyncio internal machinery, that's why the traceback is long. IFIAK Python standard library never filters such calls, asyncio is not an exception. On the other hand, well-known pytest library supports `__tracebackhide__ = True` for skipping pytest internals in test failure reports. I'm not sure if we want to do such black magic though. Plus, sometimes an information about internals is helpful to detect the actual source of the problem, I have no clear vision of how to skip internal frames easily. Yuri, maybe you have an idea? |
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| msg415476 - (view) | Author: Irit Katriel (iritkatriel) * |
Date: 2022-03-18 09:35 | |
I don't think the OP is complaining about the internal asyncio machinery frames, but rather about the repetition of the "return f.result() # May raise f.exception()." frame. I will paste the output of the script in the next comment. |
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| msg415477 - (view) | Author: Irit Katriel (iritkatriel) * |
Date: 2022-03-18 09:36 | |
>>> asyncio.run(main()) Traceback (most recent call last): File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait [Previous line repeated 7 more times] File "<stdin>", line 2, in crash Exception: crash! Traceback (most recent call last): File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait [Previous line repeated 7 more times] File "<stdin>", line 2, in crash Exception: crash! Traceback (most recent call last): File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait [Previous line repeated 7 more times] File "<stdin>", line 2, in crash Exception: crash! Traceback (most recent call last): File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait [Previous line repeated 7 more times] File "<stdin>", line 2, in crash Exception: crash! Traceback (most recent call last): File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait [Previous line repeated 7 more times] File "<stdin>", line 2, in crash Exception: crash! Traceback (most recent call last): File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait [Previous line repeated 7 more times] File "<stdin>", line 2, in crash Exception: crash! Traceback (most recent call last): File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait [Previous line repeated 7 more times] File "<stdin>", line 2, in crash Exception: crash! Traceback (most recent call last): File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait [Previous line repeated 7 more times] File "<stdin>", line 2, in crash Exception: crash! Traceback (most recent call last): File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait [Previous line repeated 7 more times] File "<stdin>", line 2, in crash Exception: crash! Traceback (most recent call last): File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 6, in main File "C:\Users\User\src\cpython\Lib\asyncio\tasks.py", line 597, in _wait_for_one return f.result() # May raise f.exception(). ^^^^^^^^^^ File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait File "<stdin>", line 2, in wait [Previous line repeated 7 more times] File "<stdin>", line 2, in crash Exception: crash! >>> |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2022-04-11 14:59:39 | admin | set | github: 86848 |
| 2022-03-18 09:37:02 | iritkatriel | set | status: open -> closed superseder: Incorrect traceback when future's exception is raised multiple times resolution: duplicate stage: resolved |
| 2022-03-18 09:36:01 | iritkatriel | set | messages: + msg415477 |
| 2022-03-18 09:35:37 | iritkatriel | set | nosy:
+ iritkatriel messages: + msg415476 |
| 2020-12-23 10:40:52 | asvetlov | set | messages: + msg383637 |
| 2020-12-19 08:09:24 | lilydjwg | create | |