[New-bugs-announce] [issue41694] python3 futures.as_completed timeout broken if future contains undefined reference

[Dallas Marlow]

New submission from Dallas Marlow <dallasmarlow at gmail.com>:

I recently noticed that timeouts do not work with futures.as_completed if a future contains an undefined variable or method. The following code runs for 30 seconds which I believe is a bug as I would expect the invalid print future to throw an exception immediately or the as_completed method throw an exception instead.

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

import concurrent.futures

with concurrent.futures.ThreadPoolExecutor() as ex:
	futures = [
		ex.submit(time.sleep, 30),
		ex.submit(print, a),
	]
	for future in concurrent.futures.as_completed(futures, timeout=1):
		_ = future.result()

----------
components: Interpreter Core
messages: 376250
nosy: dallasmarlow
priority: normal
severity: normal
status: open
title: python3 futures.as_completed timeout broken if future contains undefined reference
versions: Python 3.6, Python 3.7, Python 3.8

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue41694>
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