Upgrade to Django 1.7 - AppRegistryNotReady except

Question

I'm struggling by trying to make things work after upgrading the Django version from 1.6.7 to 1.7. It looks like I'm not able to focus on the right matter. I try to resume the situation so far.

Thing is: if I leave the command django.setup() in my wsgi.py file, when I try to access my website I get an internal server error (500). Looking at the logs, I get:

[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1] mod_wsgi (pid=23258): Target WSGI script '/home/thrasher/webapps/django/myproject.wsgi' cannot be loaded as Python module.
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1] mod_wsgi (pid=23258): Exception occurred processing WSGI script '/home/thrasher/webapps/django/myproject.wsgi'.
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1] Traceback (most recent call last):
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1]   File "/home/thrasher/webapps/django/myproject.wsgi", line 16, in <module>
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1]     application = get_wsgi_application()
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1]   File "/home/thrasher/webapps/django/lib/python2.7/django/core/wsgi.py", line 14, in get_wsgi_application
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1]     django.setup()
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1]   File "/home/thrasher/webapps/django/lib/python2.7/django/__init__.py", line 21, in setup
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1]     apps.populate(settings.INSTALLED_APPS)
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1]   File "/home/thrasher/webapps/django/lib/python2.7/django/apps/registry.py", line 78, in populate
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1]     raise RuntimeError("populate() isn't reentrant")
[Sun Oct 12 12:38:50 2014] [error] [client 127.0.0.1] RuntimeError: populate() isn't reentrant

However, if I comment the django.setup() call, trying to access the website gets me this stack trace:

Environment:


Request Method: GET
Request URL: http://www.creepyvisions.it/

Django Version: 1.7
Python Version: 2.7.8
Installed Applications:
('django.contrib.auth',
 'django.contrib.admin.apps.SimpleAdminConfig',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.sites',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.admin',
 'django.contrib.admindocs',
 'myproject.archivio',
 'sorl.thumbnail',
 'django.contrib.sitemaps',
 'rest_framework')
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware')


Traceback:
File "/home/thrasher/webapps/django/lib/python2.7/django/core/handlers/base.py" in get_response
  98.                 resolver_match = resolver.resolve(request.path_info)
File "/home/thrasher/webapps/django/lib/python2.7/django/core/urlresolvers.py" in resolve
  338.             for pattern in self.url_patterns:
File "/home/thrasher/webapps/django/lib/python2.7/django/core/urlresolvers.py" in url_patterns
  367.         patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "/home/thrasher/webapps/django/lib/python2.7/django/core/urlresolvers.py" in urlconf_module
  361.             self._urlconf_module = import_module(self.urlconf_name)
File "/usr/local/lib/python2.7/importlib/__init__.py" in import_module
  37.     __import__(name)
File "/home/thrasher/webapps/django/myproject/urls.py" in <module>
  33.                        url(r'^admin/', include(admin.site.urls)),
File "/home/thrasher/webapps/django/lib/python2.7/django/contrib/admin/sites.py" in urls
  260.         return self.get_urls(), self.app_name, self.name
File "/home/thrasher/webapps/django/lib/python2.7/django/contrib/admin/sites.py" in get_urls
  221.             self.check_dependencies()
File "/home/thrasher/webapps/django/lib/python2.7/django/contrib/admin/sites.py" in check_dependencies
  159.         if not apps.is_installed('django.contrib.admin'):
File "/home/thrasher/webapps/django/lib/python2.7/django/apps/registry.py" in is_installed
  223.         self.check_apps_ready()
File "/home/thrasher/webapps/django/lib/python2.7/django/apps/registry.py" in check_apps_ready
  124.             raise AppRegistryNotReady("Apps aren't loaded yet.")

Exception Type: AppRegistryNotReady at /
Exception Value: Apps aren't loaded yet.

For the sake of completion, this is the code related to wsgi:

myprojext.wsgi

import os
import sys

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "myproject.settings")

from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()

wgsi.py

import django
from django.core.handlers.wsgi import WSGIHandler


def get_wsgi_application():
    #django.setup()
    return WSGIHandler()

Things look very odd to me, I performed a lot of searches in the official Django docs and in various forums, but I'm still unable to get things work properly. Any suggestions would be much appreciated.

Answer 1

It turned out that the problem was a duplication, in the INSTALLED_APPS, of the django.contrib.admin. It looks that it was the root of the problem. As soon as I removed the second reference, I uncommented django.setup() in wsgi.py and things became sunny and clear again. Now everything is working fine.