I have latest celery 4.4.4. When try to run it as worker, it gives error.
$ .venv/bin/pip freeze
amqp==2.6.0
appnope==0.1.0
backcall==0.1.0
billiard==3.6.3.0
celery==4.4.4
decorator==4.4.2
importlib-metadata==1.6.0
ipython==7.15.0
ipython-genutils==0.2.0
jedi==0.17.0
kombu==4.6.10
parso==0.7.0
pexpect==4.8.0
pickleshare==0.7.5
prompt-toolkit==3.0.5
ptyprocess==0.6.0
Pygments==2.6.1
pytz==2020.1
six==1.15.0
traitlets==4.3.3
vine==1.3.0
wcwidth==0.2.3
zipp==3.1.0
packages in my virutalenv.
$ .venv/bin/celery worker
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
[2020-06-04 21:14:58,161: CRITICAL/MainProcess] Unrecoverable error: ModuleNotFoundError("No module named 'future'")
Traceback (most recent call last):
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/kombu/utils/objects.py", line 42, in __get__
return obj.__dict__[self.__name__]
KeyError: 'backend'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/worker/worker.py", line 208, in start
self.blueprint.start(self)
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/bootsteps.py", line 115, in start
self.on_start()
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/apps/worker.py", line 139, in on_start
self.emit_banner()
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/apps/worker.py", line 154, in emit_banner
' \n', self.startup_info(artlines=not use_image))),
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/apps/worker.py", line 217, in startup_info
results=self.app.backend.as_uri(),
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/kombu/utils/objects.py", line 44, in __get__
value = obj.__dict__[self.__name__] = self.__get(obj)
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/app/base.py", line 1232, in backend
return self._get_backend()
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/app/base.py", line 949, in _get_backend
self.loader)
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/app/backends.py", line 74, in by_url
return by_name(backend, loader), url
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/app/backends.py", line 54, in by_name
cls = symbol_by_name(backend, aliases)
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/kombu/utils/imports.py", line 57, in symbol_by_name
module = imp(module_name, package=package, **kwargs)
File "/Users/myuser/.pyenv/versions/3.7.4/lib/python3.7/importlib/__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
File "<frozen importlib._bootstrap>", line 983, in _find_and_load
File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 728, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/backends/rpc.py", line 19, in <module>
from . import base
File "/Users/myuser/myprj/.venv/lib/python3.7/site-packages/celery/backends/base.py", line 10, in <module>
from future.utils import raise_with_traceback
ModuleNotFoundError: No module named 'future'
This is new change added in new version of 4.4.4. How to fix this ?