DJANGO_SETTINGS_MODULE undefined error

fb_dsm_issue.txt

   Traceback (most recent call last):
    /edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/nose/loader.py line 418 in loadTestsFromName
      addr.filename, addr.module)
    /edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/nose/importer.py line 47 in importFromPath
      return self.importFromDir(dir_path, fqname)
    /edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/nose/importer.py line 94 in importFromDir
      mod = load_module(part_fqname, fh, filename, desc)
    common/lib/xmodule/xmodule/assetstore/tests/test_asset_xml.py line 12 in <module>
      from xmodule.modulestore.tests.test_assetstore import AssetStoreTestData
    common/lib/xmodule/xmodule/modulestore/tests/test_assetstore.py line 16 in <module>
      from xmodule.modulestore.tests.factories import CourseFactory
    common/lib/xmodule/xmodule/modulestore/tests/factories.py line 13 in <module>
      from factory import Factory
    /edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/factory/__init__.py line 45 in <module>
      from .django import DjangoModelFactory
    /edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/factory/django.py line 64 in <module>
      from django.db.models.loading import get_model
    /edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/django/db/__init__.py line 11 in <module>
      if DEFAULT_DB_ALIAS not in settings.DATABASES:
    /edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/django/utils/functional.py line 184 in inner
      self._setup()
    /edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/django/conf/__init__.py line 40 in _setup
      raise ImportError("Settings cannot be imported, because environment variable %s is undefined." % ENVIRONMENT_VARIABLE)
   ImportError: Settings cannot be imported, because environment variable DJANGO_SETTINGS_MODULE is undefined.