No friendly message about removal of filtersets emitted.

[rgammans]

I'm getting the following backtrace since 3.5.2 was released.

mod_wsgi (pid=107917): Exception occurred processing WSGI script '/my_project/my_app/deploy/my_app.wsgi'.
Traceback (most recent call last):
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/Django-1.8-py2.7.egg/django/core/handlers/wsgi.py", line 170, in __call__
    self.load_middleware()
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/Django-1.8-py2.7.egg/django/core/handlers/base.py", line 52, in load_middleware
    mw_instance = mw_class()
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/Django-1.8-py2.7.egg/django/middleware/locale.py", line 24, in __init__
    for url_pattern in get_resolver(None).url_patterns:
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/Django-1.8-py2.7.egg/django/core/urlresolvers.py", line 402, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/Django-1.8-py2.7.egg/django/core/urlresolvers.py", line 396, in urlconf_module
    self._urlconf_module = import_module(self.urlconf_name)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "my_project/my_app/deploy/cgi/my_app/urls.py", line 7, in <module>
    from rest_framework import routers, serializers, viewsets
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/djangorestframework-3.5.2-py2.7.egg/rest_framework/viewsets.py", line 26, in <module>
    from rest_framework import generics, mixins, views
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/djangorestframework-3.5.2-py2.7.egg/rest_framework/generics.py", line 25, in <module>
    class GenericAPIView(views.APIView):
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/djangorestframework-3.5.2-py2.7.egg/rest_framework/generics.py", line 44, in GenericAPIView
    filter_backends = api_settings.DEFAULT_FILTER_BACKENDS
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/djangorestframework-3.5.2-py2.7.egg/rest_framework/settings.py", line 220, in __getattr__
    val = perform_import(val, attr)
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/djangorestframework-3.5.2-py2.7.egg/rest_framework/settings.py", line 165, in perform_import
    return [import_from_string(item, setting_name) for item in val]
  File "my_project/my_app/deploy/python-env/lib/python2.7/site-packages/djangorestframework-3.5.2-py2.7.egg/rest_framework/settings.py", line 181, in import_from_string
    raise ImportError(msg)
ImportError: Could not import 'rest_framework.filters.DjangoFilterBackend' for API setting 'DEFAULT_FILTER_BACKENDS'. ImportError: No module named rest_framework.filterset.

with

REST_FRAMEWORK = {
    'DEFAULT_FILTER_BACKENDS': (
        'rest_framework.filters.DjangoFilterBackend',
    ),
    'DEFAULT_PARSER_CLASSES': (
        'rest_framework.parsers.JSONParser',
    ),
    'DEFAULT_RENDERER_CLASSES' : [
        'rest_framework.renderers.JSONRenderer',
    ],
    'DEFAULT_PERMISSION_CLASSES': (
        'rest_framework.permissions.IsAdminUser',
    ),
    'DEFAULT_AUTHENTICATION_CLASSES': (
        'rest_framework.authentication.SessionAuthentication',
    )

}

My reading of #4620 is that this should be a friendly warning pointing be to the direct issue. Instead I had to dig through the diff of pip freeze outputs to trace it down. No worries it's done now. BVUt it might help other later if your warning appears . ;-).

[tomchristie]

:-/

[tomchristie]

Related: #4643

[njoyard]

As is, 3.5.1+ are not compatible with code written for 3.5.0. I get that this was a bugfix (or did I understand something wrong ?) but 3.5.1 should really be called 4.0.0, and so on. Getting an ImportError because you depend on "djangorestframework>=3.5,<3.6" is really bad semver practice :(

[tomchristie]

It's not intentional. It's a bugfix causing a bug. We'll resolve it and issue a new release ASAP.