Issue 1:
Checklist

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

Subsequent groups within a chain fail #3585

Consecutive groups in chain fails #4848

task/group chains fails in some scenarios #5467

Environment & Settings

Celery version: 4.3.0

celery report Output:

software -> celery:4.3.0 (rhubarb) kombu:4.5.0 py:3.5.3

billiard:3.6.0.0 redis:3.2.1

platform -> system:Linux arch:64bit

kernel version:4.19.32-1-MANJARO imp:CPython

loader -> celery.loaders.app.AppLoader

settings -> transport:redis results:redis://redis:6379/1

broker_url: redis://redis:6379/1

result_backend: redis://redis:6379/1

Steps to Reproduce

Minimally Reproducible Test Case

from celery import group, chain
from tasks import task as t

# failing sequence
task = group([ t.si(),t.si(), chain( t.si(), group([ t.si(), t.si()]))])

# working sequence
task = group([ t.si(),t.si(), chain( t.si(), group([ t.si(), t.si()]), t.si())])

async_result = task.apply_async()
result = async_result.get()

Expected Behavior

Calling get return group result.

Actual Behavior

All task finish success but calling .get() fail with traceback:

Traceback (most recent call last):
File "/my_app.py", line 111, in add_to_queue
result = async_result.get()
File "/root/.cache/pypoetry/virtualenvs/my_app/lib/python3.7/site-packages/celery/result.py", line 697, in get
on_interval=on_interval,
File "/root/.cache/pypoetry/virtualenvs/my_app/lib/python3.7/site-packages/celery/result.py", line 815, in join_native
on_message, on_interval):
File "/root/.cache/pypoetry/virtualenvs/my_app/lib/python3.7/site-packages/celery/backends/asynchronous.py", line 137, in iter_native
if node._cache:
AttributeError: 'GroupResult' object has no attribute '_cache'

Issue 2:
Checklist

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).

Related Issues and Possible Duplicates

Related Issues

None

Possible Duplicates

None

Description

Did you all notice: http://celeryproject.org/ is not available?

This docs domain DO work: https://docs.celeryq.dev/en/stable/

I guess the first one is important because it is the website google indexes -> you can reach it from google.

Suggestions

(: