无法导入名称heartbeat_expires

Question

我正在尝试与Django项目Heroku和S3交朋友。安装Celery后

  

cannot import name heartbeat_expires

回溯：

Environment:


Request Method: GET
Request URL: http://protected-ocean-4209.herokuapp.com/

Django Version: 1.4
Python Version: 2.7.4
Installed Applications:
('django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.sites',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.admin',
 'django.contrib.admindocs',
 'django.contrib.flatpages',
 'mptt',
 'zakai',
 'easy_thumbnails',
 'storages',
 'queued_storage',
 'djcelery')
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.contrib.flatpages.middleware.FlatpageFallbackMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware')


Traceback:
File "/app/.heroku/python/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  101.                             request.path_info)
File "/app/.heroku/python/lib/python2.7/site-packages/django/core/urlresolvers.py" in resolve
  298.             for pattern in self.url_patterns:
File "/app/.heroku/python/lib/python2.7/site-packages/django/core/urlresolvers.py" in url_patterns
  328.         patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "/app/.heroku/python/lib/python2.7/site-packages/django/core/urlresolvers.py" in urlconf_module
  323.             self._urlconf_module = import_module(self.urlconf_name)
File "/app/.heroku/python/lib/python2.7/site-packages/django/utils/importlib.py" in import_module
  35.     __import__(name)
File "/app/zakailtd/urls.py" in <module>
  13. admin.autodiscover()
File "/app/.heroku/python/lib/python2.7/site-packages/django/contrib/admin/__init__.py" in autodiscover
  29.             import_module('%s.admin' % app)
File "/app/.heroku/python/lib/python2.7/site-packages/django/utils/importlib.py" in import_module
  35.     __import__(name)
File "/app/.heroku/python/lib/python2.7/site-packages/django/contrib/auth/admin.py" in <module>
  171. admin.site.register(Group, GroupAdmin)
File "/app/.heroku/python/lib/python2.7/site-packages/django/contrib/admin/sites.py" in register
  92.             validate(admin_class, model)
File "/app/.heroku/python/lib/python2.7/site-packages/django/contrib/admin/validation.py" in validate
  22.     models.get_apps()
File "/app/.heroku/python/lib/python2.7/site-packages/django/db/models/loading.py" in get_apps
  126.         self._populate()
File "/app/.heroku/python/lib/python2.7/site-packages/django/db/models/loading.py" in _populate
  67.                     self.load_app(app_name)
File "/app/.heroku/python/lib/python2.7/site-packages/django/db/models/loading.py" in load_app
  88.             models = import_module('.models', app_name)
File "/app/.heroku/python/lib/python2.7/site-packages/django/utils/importlib.py" in import_module
  35.     __import__(name)
File "/app/.heroku/python/lib/python2.7/site-packages/djcelery/models.py" in <module>
  13. from celery.events.state import heartbeat_expires

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