Data download in Json format throws error

[nruggero]

Here is the traceback:

Environment:


Request Method: GET
Request URL: http://wholecellkb.stanford.edu/export/Mgenitalium?species=Mgenitalium&model_type=Chromosome&model_type=ChromosomeFeature&model_type=Compartment&model_type=Gene&model_type=Metabolite&model_type=Note&model_type=Parameter&model_type=Pathway&model_type=Process&model_type=ProteinComplex&model_type=ProteinMonomer&model_type=Reaction&model_type=Reference&model_type=Species&model_type=State&model_type=Stimulus&model_type=TranscriptionUnit&model_type=TranscriptionalRegulation&model_type=Type&all_model_types=True&format=json

Django Version: 1.4
Python Version: 2.7.2
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_extensions',
 'public',
 'haystack')
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')


Traceback:
File "/opt/python2.7.2/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  111.                         response = callback(request, *callback_args, **callback_kwargs)
File "/home/projects/WholeCellKB/apache/../public/views.py" in exportData
  947.          models = models)
File "/home/projects/WholeCellKB/apache/../public/helpers.py" in render_queryset_to_response
  436.      for obj in queryset.iterator():

Exception Type: AttributeError at /export/Mgenitalium
Exception Value: 'itertools.chain' object has no attribute 'iterator'