Overnight django stopped working, possibly because of an automatic package upgrade on the server. Its wsgi script now fails to load in production, but running the development server works fine. What might cause the following error?
mod_wsgi (pid=27634): Target WSGI script '/var/www/.../wsgi.py' cannot be loaded as Python module. mod_wsgi (pid=27634): Exception occurred processing WSGI script '/var/www/.../wsgi.py'. Traceback (most recent call last): File "/var/www/.../wsgi.py", line 13, in <module> from django.core.wsgi import get_wsgi_application File "/usr/local/lib/python2.7/dist-packages/django/core/wsgi.py", line 2, in <module> from django.core.handlers.wsgi import WSGIHandler File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/wsgi.py", line 10, in <module> from django import http File "/usr/local/lib/python2.7/dist-packages/django/http/__init__.py", line 5, in <module> from django.http.response import ( File "/usr/local/lib/python2.7/dist-packages/django/http/response.py", line 13, in <module> from django.core.serializers.json import DjangoJSONEncoder File "/usr/local/lib/python2.7/dist-packages/django/core/serializers/__init__.py", line 23, in <module> from django.core.serializers.base import SerializerDoesNotExist File "/usr/local/lib/python2.7/dist-packages/django/core/serializers/base.py", line 4, in <module> from django.db import models File "/usr/local/lib/python2.7/dist-packages/django/db/models/__init__.py", line 4, in <module> from django.db.models import signals # NOQA ImportError: cannot import name signals
The wsgi.py file is as follows:
import os os.environ.setdefault("DJANGO_SETTINGS_MODULE", "....settings") from django.core.wsgi import get_wsgi_application application = get_wsgi_application()
This worked 24 hours ago and has stopped working - I've tried django 1.10 and 1.10.3 but both exhibit the same symptoms. apache 2.4.18, python 2.7.12.
The file /usr/local/lib/python2.7/dist-packages/django/db/models/signals.py exists, so in principle there shouldn't be anything stopping the import.