deadlock detected when trying to start server : <p>I have a simple application where I am using both django and django-rest-framework.</p>

<p>Quite often, when I try to start the local server (<code>python manage.py runserver</code>), I get the following exception:</p>

<pre><code>Watching for file changes with StatReloader
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/project/venv/lib/python3.7/site-packages/django/template/utils.py", line 66, in __getitem__
    return self._engines[alias]
KeyError: 'django'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/Cellar/python/3.7.2_2/Frameworks/Python.framework/Versions/3.7/lib/python3.7/threading.py", line 917, in _bootstrap_inner
    self.run()
  File "/usr/local/Cellar/python/3.7.2_2/Frameworks/Python.framework/Versions/3.7/lib/python3.7/threading.py", line 865, in run
    self._target(*self._args, **self._kwargs)
  File "/project/venv/lib/python3.7/site-packages/django/utils/autoreload.py", line 54, in wrapper
    fn(*args, **kwargs)
  File "/project/venv/lib/python3.7/site-packages/django/core/management/commands/runserver.py", line 117, in inner_run
    self.check(display_num_errors=True)
  File "/project/venv/lib/python3.7/site-packages/django/core/management/base.py", line 390, in check
    include_deployment_checks=include_deployment_checks,
  File "/project/venv/lib/python3.7/site-packages/django/core/management/base.py", line 377, in _run_checks
    return checks.run_checks(**kwargs)
  File "/project/venv/lib/python3.7/site-packages/django/core/checks/registry.py", line 72, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/project/venv/lib/python3.7/site-packages/django/contrib/admin/checks.py", line 80, in check_dependencies
    for engine in engines.all():
  File "/project/venv/lib/python3.7/site-packages/django/template/utils.py", line 90, in all
    return [self[alias] for alias in self]
  File "/project/venv/lib/python3.7/site-packages/django/template/utils.py", line 90, in &lt;listcomp&gt;
    return [self[alias] for alias in self]
  File "/project/venv/lib/python3.7/site-packages/django/template/utils.py", line 81, in __getitem__
    engine = engine_cls(params)
  File "/project/venv/lib/python3.7/site-packages/django/template/backends/django.py", line 25, in __init__
    options['libraries'] = self.get_templatetag_libraries(libraries)
  File "/project/venv/lib/python3.7/site-packages/django/template/backends/django.py", line 43, in get_templatetag_libraries
    libraries = get_installed_libraries()
  File "/project/venv/lib/python3.7/site-packages/django/template/backends/django.py", line 108, in get_installed_libraries
    for name in get_package_libraries(pkg):
  File "/project/venv/lib/python3.7/site-packages/django/template/backends/django.py", line 121, in get_package_libraries
    module = import_module(entry[1])
  File "/project/venv/lib/python3.7/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "&lt;frozen importlib._bootstrap&gt;", line 1006, in _gcd_import
  File "&lt;frozen importlib._bootstrap&gt;", line 983, in _find_and_load
  File "&lt;frozen importlib._bootstrap&gt;", line 967, in _find_and_load_unlocked
  File "&lt;frozen importlib._bootstrap&gt;", line 677, in _load_unlocked
  File "&lt;frozen importlib._bootstrap_external&gt;", line 728, in exec_module
  File "&lt;frozen importlib._bootstrap&gt;", line 219, in _call_with_frames_removed
  File "/project/venv/lib/python3.7/site-packages/rest_framework/templatetags/rest_framework.py", line 15, in &lt;module&gt;
    from rest_framework.renderers import HTMLFormRenderer
  File "/project/venv/lib/python3.7/site-packages/rest_framework/renderers.py", line 20, in &lt;module&gt;
    from django.test.client import encode_multipart
  File "/project/venv/lib/python3.7/site-packages/django/test/client.py", line 23, in &lt;module&gt;
    from django.test import signals
  File "&lt;frozen importlib._bootstrap&gt;", line 980, in _find_and_load
  File "&lt;frozen importlib._bootstrap&gt;", line 149, in __enter__
  File "&lt;frozen importlib._bootstrap&gt;", line 94, in acquire
_frozen_importlib._DeadlockError: deadlock detected by _ModuleLock('django.test.signals') at 4420467792

Performing system checks...
</code></pre>

<p>After a couple of retries, the server starts successfully. Therefore, it is not a show-stopper but it is quite annoying.</p>

<p>Since I am quite new to Django, I was wondering if there was a way to prevent such an error.</p>
