Issue 1:
Checklist

I have verified that the issue exists against the master branch of Celery.

This has already been asked to the discussion group first.

I have read the relevant section in the

contribution guide

on reporting bugs.

I have checked the issues list

for similar or identical bug reports.

I have checked the pull requests list

for existing proposed fixes.

I have checked the commit log

to find out if the bug was already fixed in the master branch.

I have included all related issues and possible duplicate issues

in this issue (If there are none, check this box anyway).

Mandatory Debugging Information

I have included the output of celery -A proj report in the issue.

(if you are not able to do this, then at least specify the Celery

version affected).

I have verified that the issue exists against the master branch of Celery.

I have included the contents of pip freeze in the issue.

I have included all the versions of all the external dependencies required

to reproduce this bug.

Optional Debugging Information

I have tried reproducing the issue on more than one Python version

and/or implementation.

I have tried reproducing the issue on more than one message broker and/or

result backend.

I have tried reproducing the issue on more than one version of the message

broker and/or result backend.

I have tried reproducing the issue on more than one operating system.

I have tried reproducing the issue on more than one workers pool.

I have tried reproducing the issue with autoscaling, retries,

ETA/Countdown & rate limits disabled.

I have tried reproducing the issue after downgrading

and/or upgrading Celery and its dependencies.

Related Issues and Possible Duplicates

Related Issues

None

Possible Duplicates

None

Environment & Settings

Celery version: 5.1.2

celery report Output:

celery@Guan-Johns-MacBook.local v5.1.2 (sun-harmonics)

macOS-10.15.7-x86_64-i386-64bit 2021-07-20 16:30:46

[config]

.> app: tasks:0x10ccc9f40

.> transport: redis://localhost:6379//

.> results: disabled://

.> concurrency: 1 (prefork)

.> task events: ON

[queues]

.> celery exchange=celery(direct) key=celery

[tasks]

. tasks.add

[2021-07-20 16:30:46,948: INFO/MainProcess] Connected to redis://localhost:6379//

[2021-07-20 16:30:46,957: INFO/MainProcess] mingle: searching for neighbors

[2021-07-20 16:30:47,994: INFO/MainProcess] mingle: all alone

[2021-07-20 16:30:48,014: INFO/MainProcess] celery@Guan-Johns-MacBook.local ready.

Steps to Reproduce

Required Dependencies

Minimal Python Version: 3.8.5

Minimal Celery Version: 5.1.2

Minimal Kombu Version: 5.1.0

Minimal Broker Version: Redis 6.2.4

Minimal Result Backend Version: N/A or Unknown

Minimal OS and/or Kernel Version: macOS-10.15.7

Minimal Broker Client Version: N/A or Unknown

Minimal Result Backend Client Version: N/A or Unknown

Python Packages

pip freeze Output:

Other Dependencies

N/A

Minimally Reproducible Test Case

from celery import Celery
app = Celery('tasks',
broker='redis://localhost',
broker_transport_options = {'visibility_timeout': 0},
task_acks_late=True,
task_acks_on_failure_or_timeout=False,
)
print(app.conf['task_acks_on_failure_or_timeout'])

Expected Behavior

expected 'False' output.

Actual Behavior

but 'True' output. I can not set task_acks_on_failure_or_timeout to False (default:True)

I think the reason is __autoset(), 'if value' will filter out all False value.

https://github.com/celery/celery/blob/master/celery/app/base.py#L325

def __autoset(self, key, value):
if value:
self._preconf[key] = value
self._preconf_set_by_auto.add(key)

Issue 2:
Checklist

I have verified that the issue exists against the master branch of Celery.

This has already been asked to the discussion group first.

I have read the relevant section in the

contribution guide

on reporting bugs.

I have checked the issues list

for similar or identical bug reports.

I have checked the pull requests list

for existing proposed fixes.

I have checked the commit log

to find out if the bug was already fixed in the master branch.

I have included all related issues and possible duplicate issues

in this issue (If there are none, check this box anyway).

Mandatory Debugging Information

I have verified that the issue exists against the master branch of Celery.

Optional Debugging Information

isAlive was deprecated and removed in Python 3.9 . Celery has the deprecation warning that will become error in Python 3.9 .

https://travis-ci.org/celery/celery/jobs/628813003#L3262-L3263

Relevant CPython PR : python/cpython#15225