Testing against Django installed in '/tmp/buildd/python-django-1.11~alpha1/django' with up to 4 processes
Creating test database for alias 'default'...
Cloning test database for alias 'default'...
Cloning test database for alias 'default'...
Cloning test database for alias 'default'...
Creating test database for alias 'other'...
Cloning test database for alias 'other'...
Cloning test database for alias 'other'...
Cloning test database for alias 'other'...
System check identified no issues (0 silenced).
Traceback (most recent call last):
  File "./runtests.py", line 492, in <module>
    options.exclude_tags,
  File "./runtests.py", line 286, in django_tests
    extra_tests=extra_tests,
  File "/tmp/buildd/python-django-1.11~alpha1/django/test/runner.py", line 603, in run_tests
    result = self.run_suite(suite)
  File "/tmp/buildd/python-django-1.11~alpha1/django/test/runner.py", line 567, in run_suite
    return runner.run(suite)
  File "/usr/lib/python2.7/unittest/runner.py", line 151, in run
    test(result)
  File "/usr/lib/python2.7/unittest/suite.py", line 70, in __call__
    return self.run(*args, **kwds)
  File "/tmp/buildd/python-django-1.11~alpha1/django/test/runner.py", line 370, in run
    subsuite_index, events = test_results.next(timeout=0.1)
  File "/usr/lib/python2.7/multiprocessing/pool.py", line 668, in next
    raise value
TypeError: can't pickle traceback objects


test_disabled_serving (staticfiles_tests.test_views.TestServeDisabled) failed:

    ImproperlyConfigured(u"AUTH_USER_MODEL refers to model 'auth.User' that
    has not been installed",)

Unfortunately, tracebacks cannot be pickled, making it impossible for the
parallel test runner to handle this exception cleanly.

In order to see the traceback, you should install tblib:

    pip install tblib