'NoneType' object has no attribute '_meta' in manage.py dumpdata auth.user

[Jerome Leclanche]

In 1.10rc1 I get the following when running ./manage.py dumpdata auth.user --traceback::

[Traceback (most recent call last):
  File "./manage.py", line 11, in <module>
    execute_from_command_line(sys.argv)
  File "/home/adys/.local/share/virtualenvs/hs/lib/python3.5/site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
    utility.execute()
  File "/home/adys/.local/share/virtualenvs/hs/lib/python3.5/site-packages/django/core/management/__init__.py", line 359, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/adys/.local/share/virtualenvs/hs/lib/python3.5/site-packages/django/core/management/base.py", line 305, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/adys/.local/share/virtualenvs/hs/lib/python3.5/site-packages/django/core/management/base.py", line 356, in execute
    output = self.handle(*args, **options)
  File "/home/adys/.local/share/virtualenvs/hs/lib/python3.5/site-packages/django/core/management/commands/dumpdata.py", line 200, in handle
    object_count=object_count,
  File "/home/adys/.local/share/virtualenvs/hs/lib/python3.5/site-packages/django/core/serializers/__init__.py", line 129, in serialize
    s.serialize(queryset, **options)
  File "/home/adys/.local/share/virtualenvs/hs/lib/python3.5/site-packages/django/core/serializers/base.py", line 79, in serialize
    for count, obj in enumerate(queryset, start=1):
  File "/home/adys/.local/share/virtualenvs/hs/lib/python3.5/site-packages/django/core/management/commands/dumpdata.py", line 161, in get_objects
    models = serializers.sort_dependencies(app_list.items())
  File "/home/adys/.local/share/virtualenvs/hs/lib/python3.5/site-packages/django/core/serializers/__init__.py", line 195, in sort_dependencies
    if field.remote_field.through._meta.auto_created:
AttributeError: 'NoneType' object has no attribute '_meta'

For reference, here is my user model:
​https://github.com/HearthSim/HSReplay.net/blob/51c269f2cc329d859df70705e2181666d443434c/hsreplaynet/accounts/models.py#L26-L36

[Tim Graham]

Can you try to put together a minimal sample project to reproduce the crash and ​bisect to determine where the behavior changed?

[Tim Graham]

Sorry, but the project you provide is too complex and I'm spending too much time trying to debug this. Reopen if you can put together a more minimal project that reproduces the problem and hopefully also bisect to find the commit where things changed. Thanks!