Can't inspect with destination option

[aszubarev]

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:

celery report Output:

software -> celery:5.0.0 (singularity) kombu:5.0.2 py:3.8.5
            billiard:3.6.3.0 py-amqp:5.0.1
platform -> system:Darwin arch:64bit
            kernel version:18.7.0 imp:CPython
loader   -> celery.loaders.app.AppLoader
settings -> transport:amqp results:disabled

deprecated_settings: None

Steps to Reproduce

Required Dependencies

• Minimal Python Version: N/A or Unknown
• Minimal Celery Version: 5.0.0
• Minimal Kombu Version: 5.0.2
• Minimal Broker Version: N/A or Unknown
• Minimal Result Backend Version: N/A or Unknown
• Minimal OS and/or Kernel Version: N/A or Unknown
• Minimal Broker Client Version: N/A or Unknown
• Minimal Result Backend Client Version: N/A or Unknown

Python Packages

pip freeze Output:

amqp==5.0.1
appdirs==1.4.4
appnope==0.1.0
asgiref==3.2.10
astor==0.8.1
attrs==20.2.0
backcall==0.2.0
bandit==1.6.2
bcrypt==3.2.0
billiard==3.6.3.0
blinker==1.4
celery==5.0.0
certifi==2020.6.20
cffi==1.14.3
chardet==3.0.4
click==7.1.2
click-default-group==1.2.2
click-didyoumean==0.0.3
click-repl==0.1.6
colorama==0.4.3
coreapi==2.3.3
coreschema==0.0.4
coverage==5.3
darglint==1.5.4
decorator==4.4.2
dennis==0.9
Django==3.0.10
django-admin-tools==0.9.0
django-autocomplete-light==3.5.0
django-coverage-plugin==1.8.0
django-csp==3.7
django-debug-toolbar==2.2
django-extensions==3.0.9
django-feature-policy==3.4.0
django-filter==2.4.0
django-health-check==3.14.1
django-http-referrer-policy==1.0.1
django-lifecycle==0.7.7
django-migration-linter==2.4.0
django-querycount==0.7.0
django-split-settings==1.0.1
django-stubs==1.5.0
django-test-migrations==1.0.0
djangorestframework==3.11.1
docutils==0.16
dotenv-linter==0.1.3
dparse==0.5.1
drf-yasg==1.17.1
eradicate==1.0
Faker==4.1.3
flake8==3.8.3
flake8-bandit==2.1.2
flake8-broken-line==0.2.1
flake8-bugbear==19.8.0
flake8-commas==2.0.0
flake8-comprehensions==3.2.3
flake8-debugger==3.2.1
flake8-django==1.1.1
flake8-docstrings==1.5.0
flake8-eradicate==0.3.0
flake8-isort==3.0.1
flake8-logging-format==0.6.0
flake8-plugin-utils==1.3.1
flake8-polyfill==1.0.2
flake8-pytest-style==1.3.0
flake8-quotes==2.1.2
flake8-rst-docstrings==0.0.12
flake8-string-format==0.2.3
flower==0.9.5
gitdb==4.0.5
GitPython==3.1.8
gunicorn==20.0.4
humanize==2.6.0
hypothesis==5.36.0
idna==2.10
importlib-metadata==1.1.3
inflection==0.5.1
iniconfig==1.0.1
ipython==7.18.1
ipython-genutils==0.2.0
isort==4.3.21
itypes==1.2.0
jedi==0.17.2
Jinja2==2.11.2
kombu==5.0.2
MarkupSafe==1.1.1
mccabe==0.6.1
more-itertools==8.5.0
mypy==0.770
mypy-extensions==0.4.3
nplusone==1.0.0
orjson==3.3.1
packaging==20.4
parso==0.7.1
pbr==5.5.0
pep8-naming==0.9.1
pexpect==4.8.0
pickleshare==0.7.5
pluggy==0.13.1
ply==3.11
polib==1.1.0
prometheus-client==0.8.0
prompt-toolkit==3.0.7
psycopg2==2.8.6
ptyprocess==0.6.0
py==1.9.0
pycodestyle==2.6.0
pycparser==2.20
pydantic==1.6.1
pydocstyle==5.1.1
pyflakes==2.2.0
Pygments==2.7.1
PyJWT==1.7.1
pyparsing==2.4.7
pytest==6.0.2
pytest-cov==2.10.1
pytest-deadfixtures==2.2.1
pytest-django==3.10.0
pytest-randomly==3.4.1
pytest-testmon==1.0.3
pytest-timeout==1.4.2
python-dateutil==2.8.1
python-decouple==3.3
pytz==2020.1
PyYAML==5.3.1
requests==2.24.0
restructuredtext-lint==1.3.1
ruamel.yaml==0.16.12
ruamel.yaml.clib==0.2.2
safety==1.9.0
sentry-sdk==0.17.8
six==1.15.0
smmap==3.0.4
snowballstemmer==2.0.0
sortedcontainers==2.2.2
sqlparse==0.3.1
stevedore==3.2.2
structlog==20.1.0
testfixtures==6.14.2
text-unidecode==1.3
toml==0.10.1
tornado==6.0.4
traitlets==5.0.4
typed-ast==1.4.1
typing-extensions==3.7.4.3
uritemplate==3.0.1
urllib3==1.25.10
urlman==1.3.0
vine==5.0.0
wcwidth==0.2.5
wemake-python-styleguide==0.14.1
wrapt==1.12.1
zipp==3.2.0

Other Dependencies

N/A

Minimally Reproducible Test Case

celery -A proj inspect ping -d celery@$HOSTNAME

Expected Behavior

->  celery@$HOSTNAME: OK
        pong

Actual Behavior

Traceback (most recent call last):
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/bin/celery", line 8, in <module>
    sys.exit(main())
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/celery/__main__.py", line 15, in main
    sys.exit(_main())
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/celery/bin/celery.py", line 150, in main
    return celery(auto_envvar_prefix="CELERY")
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/click/core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/click/decorators.py", line 21, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/celery/bin/control.py", line 125, in inspect
    replies = ctx.obj.app.control.inspect(timeout=timeout,
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/celery/app/control.py", line 97, in _request
    return self._prepare(self.app.control.broadcast(
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/celery/app/control.py", line 477, in broadcast
    return self.mailbox(conn)._broadcast(
  File "/Users/aszubarev/Library/Caches/pypoetry/virtualenvs/service-notification-py-xHAuYcng-py3.8/lib/python3.8/site-packages/kombu/pidbox.py", line 319, in _broadcast
    raise ValueError(
ValueError: destination must be a list/tuple not <class 'set'>
Sentry is attempting to send 0 pending error messages
Waiting up to 2 seconds
Press Ctrl-C to quit

[aszubarev]

celery/celery/bin/base.py

Line 171 in 8a92b71

return set(text.str_to_list(value))

CommaSeparatedList return set instead list.
_broadcast method of kombu Mailbox does not support set

https://github.com/celery/kombu/blob/7b2578b19ba4b1989b722f6f6e7efee2a1a4d86a/kombu/pidbox.py#L319