id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
27360	Make it easier to track down the offending models for AlreadyRegistered exceptions	Ed Morley	Quentin Fulsher	"I've just updated 20+ packages locally in a project's requirements file, one of which has caused:

{{{
[2016-10-18 15:00:18,667] ERROR [django.request:256] Internal Server Error: /browserid/csrf/
Traceback (most recent call last):
  File ""/home/vagrant/venv/local/lib/python2.7/site-packages/django/core/handlers/base.py"", line 223, in get_response
    response = middleware_method(request, response)
  File ""/home/vagrant/venv/local/lib/python2.7/site-packages/debug_toolbar/middleware.py"", line 129, in process_response
    panel.generate_stats(request, response)
  File ""/home/vagrant/venv/local/lib/python2.7/site-packages/debug_toolbar/panels/request.py"", line 41, in generate_stats
    match = resolve(request.path)
  File ""/home/vagrant/venv/local/lib/python2.7/site-packages/django/core/urlresolvers.py"", line 521, in resolve
    return get_resolver(urlconf).resolve(path)
  File ""/home/vagrant/venv/local/lib/python2.7/site-packages/django/core/urlresolvers.py"", line 365, in resolve
    for pattern in self.url_patterns:
  File ""/home/vagrant/venv/local/lib/python2.7/site-packages/django/core/urlresolvers.py"", line 401, in url_patterns
    patterns = getattr(self.urlconf_module, ""urlpatterns"", self.urlconf_module)
  File ""/home/vagrant/venv/local/lib/python2.7/site-packages/django/core/urlresolvers.py"", line 395, 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 ""/home/vagrant/treeherder/treeherder/config/urls.py"", line 12, in <module>
    browserid_admin.copy_registry(admin.site)
  File ""/home/vagrant/venv/local/lib/python2.7/site-packages/django_browserid/admin.py"", line 39, in copy_registry
    self.register(model, modeladmin.__class__)
  File ""/home/vagrant/venv/local/lib/python2.7/site-packages/django/contrib/admin/sites.py"", line 90, in register
    raise AlreadyRegistered('The model %s is already registered' % model.__name__)
AlreadyRegistered: The model Site is already registered
}}}

This model isn't defined in the project's own models so in this particular case it must be django-browserid now clashing with one of the packages that was updated.

Rather than having to bisect, it would be much more helpful if this exception gave more details about the already-registered model, so I know which package/app is clashing with the later app's attempts to re-register it."	Cleanup/optimization	closed	contrib.admin	1.8	Normal	fixed		django@… qfulsher@…	Accepted	1	0	0	0	0	0