_frozen_importlib._DeadlockError: deadlock detected by _ModuleLock('django.test.signals')

[anthonygoslar]

I've been writing some signals for a Django project
Django==2.2
Python==3.6.8
PostgreSQL==11.3

After writing and testing some pre_save and post_save signals which update product cart totals based on products inputted, I sometimes get a frozen import DeadLockError (terminal readout below'. Tracing it back, it seems to be occurring with swagger urls. I commented out the swagger urls in my project urls file and the error disappears.

The signals are not a part of any models currently serialized by Django-Restful-Framework. I'll be developing the API at a later stage.

Any ideas what may be causing this?

`Watching for file changes with StatReloader
Performing system checks...

Traceback (most recent call last):
File "manage.py", line 15, in
execute_from_command_line(sys.argv)
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/core/management/init.py", line 381, in execute_from_command_line
utility.execute()
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/core/management/init.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/core/management/base.py", line 323, in run_from_argv
self.execute(*args, **cmd_options)
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/core/management/commands/runserver.py", line 60, in execute
super().execute(*args, **options)
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/core/management/base.py", line 364, in execute
output = self.handle(*args, **options)
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/core/management/commands/runserver.py", line 95, in handle
self.run(**options)
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/core/management/commands/runserver.py", line 102, in run
autoreload.run_with_reloader(self.inner_run, **options)
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/utils/autoreload.py", line 579, in run_with_reloader
start_django(reloader, main_func, *args, **kwargs)
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/utils/autoreload.py", line 564, in start_django
reloader.run(django_main_thread)
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/utils/autoreload.py", line 272, in run
get_resolver().urlconf_module
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/utils/functional.py", line 80, in get
res = instance.dict[self.name] = self.func(instance)
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/urls/resolvers.py", line 564, in urlconf_module
return import_module(self.urlconf_name)
File "/Users/username/.pyenv/versions/project/lib/python3.6/importlib/init.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 994, in _gcd_import
File "", line 971, in _find_and_load
File "", line 955, in _find_and_load_unlocked
File "", line 665, in _load_unlocked
File "", line 678, in exec_module
File "", line 219, in _call_with_frames_removed
File "/Users/username/workspace/project/backend/src/project/urls.py", line 6, in
from rest_framework_swagger.views import get_swagger_view
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/rest_framework_swagger/views.py", line 3, in
from rest_framework.renderers import CoreJSONRenderer
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/rest_framework/renderers.py", line 20, in
from django.test.client import encode_multipart
File "/Users/username/.pyenv/versions/project/lib/python3.6/site-packages/django/test/client.py", line 23, in
from django.test import signals
File "", line 968, in _find_and_load
File "", line 149, in enter
File "", line 94, in acquire
_frozen_importlib._DeadlockError: deadlock detected by _ModuleLock('django.test.signals') at 4728136760`

[feruzoripov]

Try remove pycache folders in all directories and restart virtualenv. It worked for me.

[bennett-jacob]

@feruzoripov this is not a solution.

[miokyuk]

I have the same error. may be some object get the threading locker but dont release.
In my project, I use apscheduler to run interval job (interval 30s), use SQLAchemy as the jobstore. when shutdown the server for a moment(>60s,a job should run if not shutdown),then restart appear that error. I delete that cron job info in database, its ok.
I dont konw how to solve it.