title: When I run the full test suite in Django, I get errors about missing MessageMiddleware
body: <p>My app is called abcapp. I am running Django 1.5b1 on Python 2.7. The same issue happens in the latest trunk release of django.</p>
  
  <p>When I run <code>manage.py test abcapp</code> all tests which I have written pass.</p>
  
  <p>When I run <code>manage.py test</code> I get a cascade of failures. The first of these failures is shown:</p>
  
  <pre><code>Traceback (most recent call last):
    File "C:\Program Files\Django-1.5b1\django\core\handlers\base.py", line 116, in get_response
      response = callback(request, *callback_args, **callback_kwargs)
    File "C:\Program Files\Django-1.5b1\django\views\decorators\cache.py", line 89, in _wrapped_view_func
      response = view_func(request, *args, **kwargs)
    File "C:\Program Files\Django-1.5b1\django\contrib\messages\tests\urls.py", line 30, in add
      getattr(messages, message_type)(request, msg)
    File "C:\Program Files\Django-1.5b1\django\contrib\messages\api.py", line 70, in debug
      fail_silently=fail_silently)
    File "C:\Program Files\Django-1.5b1\django\contrib\messages\api.py", line 22, in add_message
      raise MessageFailure('You cannot add messages without installing '
  MessageFailure: You cannot add messages without installing django.contrib.messages.middleware.MessageMiddleware
  </code></pre>
  
  <p>The test results are:</p>
  
  <pre><code>======================================================================
  FAIL: test_clearsessions_command (django.contrib.sessions.tests.FileSessionTests)
  ----------------------------------------------------------------------
  Traceback (most recent call last):
    File "C:\Program Files\Django-1.5b1\django\test\utils.py", line 213, in inner
      return test_func(*args, **kwargs)
    File "C:\Program Files\Django-1.5b1\django\contrib\sessions\tests.py", line 444, in test_clearsessions_command
      self.assertEqual(1, count_sessions())
  AssertionError: 1 != 2
  
  ----------------------------------------------------------------------
  Ran 474 tests in 5.768s
  
  FAILED (failures=1, skipped=141, expected failures=1)
  </code></pre>
  
  <p>Contrary to the messages, I do have <code>django.contrib.messages.middleware.MessageMiddleware</code> in my <code>MIDDLEWARE_CLASSES</code>. The value of my <code>MIDDLEWARE_CLASSES</code> is below. I use messages within my app without any issues.</p>
  
  <pre><code>MIDDLEWARE_CLASSES = (
      'django.middleware.common.CommonMiddleware',
      'django.contrib.sessions.middleware.SessionMiddleware',
      'django.middleware.csrf.CsrfViewMiddleware',
      'django.contrib.messages.middleware.MessageMiddleware',
      'django.contrib.auth.middleware.AuthenticationMiddleware',
      'debug_toolbar.middleware.DebugToolbarMiddleware',
  )
  </code></pre>
  
  <p>Can anyone shed some light on this issue? While I can run my own tests only, I would like to run the entire suite to ensure proper quality control.</p>
  
  <p>Research results: I noticed through my own testing, that when the test http Client is used, none of the middleware is loaded. I discovered this when I was trying to test my own middleware through web requests in the test Client. If that is the case, would this mean that there is untestable code in the djanog core?</p>