Same here. Just did a clean install using devstack.

Here's my log:

Environment:


Request Method: GET
Request URL: http://localhost:8080/

Django Version: 1.5.5
Python Version: 2.7.3
Installed Applications:
['openstack_dashboard.dashboards.project',
 'openstack_dashboard.dashboards.admin',
 'openstack_dashboard.dashboards.settings',
 'openstack_dashboard',
 'django.contrib.contenttypes',
 'django.contrib.auth',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.humanize',
 'compressor',
 'horizon',
 'openstack_auth']
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'horizon.middleware.HorizonMiddleware',
 'django.middleware.doc.XViewMiddleware',
 'django.middleware.locale.LocaleMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware')


Traceback:
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
  92.                     response = middleware_method(request)
File "/usr/local/lib/python2.7/dist-packages/django/middleware/locale.py" in process_request
  21.         check_path = self.is_language_prefix_patterns_used()
File "/usr/local/lib/python2.7/dist-packages/django/middleware/locale.py" in is_language_prefix_patterns_used
  56.         for url_pattern in get_resolver(None).url_patterns:
File "/usr/local/lib/python2.7/dist-packages/django/core/urlresolvers.py" in url_patterns
  347.         patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "/usr/local/lib/python2.7/dist-packages/django/core/urlresolvers.py" in urlconf_module
  342.             self._urlconf_module = import_module(self.urlconf_name)
File "/usr/local/lib/python2.7/dist-packages/django/utils/importlib.py" in import_module
  35.     __import__(name)
File "/opt/stack/horizon/openstack_dashboard/wsgi/../../openstack_dashboard/urls.py" in <module>
  38.     url(r'', include(horizon.urls))
File "/usr/local/lib/python2.7/dist-packages/django/conf/urls/__init__.py" in include
  26.     patterns = getattr(urlconf_module, 'urlpatterns', urlconf_module)
File "/usr/local/lib/python2.7/dist-packages/django/utils/functional.py" in inner
  204.             self._setup()
File "/usr/local/lib/python2.7/dist-packages/django/utils/functional.py" in _setup
  270.         self._wrapped = self._setupfunc()
File "/opt/stack/horizon/openstack_dashboard/wsgi/../../horizon/base.py" in url_patterns
  733.             return self._urls()[0]
File "/opt/stack/horizon/openstack_dashboard/wsgi/../../horizon/base.py" in _urls
  744.             dash._autodiscover()
File "/opt/stack/horizon/openstack_dashboard/wsgi/../../horizon/base.py" in _autodiscover
  517.                 import_module('.%s.panel' % panel, package)
File "/usr/local/lib/python2.7/dist-packages/django/utils/importlib.py" in import_module
  35.     __import__(name)
File "/opt/stack/horizon/openstack_dashboard/wsgi/../../openstack_dashboard/dashboards/admin/domains/panel.py" in <module>
  21. from openstack_dashboard.api import keystone
File "/opt/stack/horizon/openstack_dashboard/wsgi/../../openstack_dashboard/api/__init__.py" in <module>
  36. from openstack_dashboard.api import base

Exception Type: ImportError at /
Exception Value: cannot import name base