find . -name tests.py -print0 | xargs -0 -Ixxx ./manage.py test xxx --settings=project_name.conf.test.settings

OSError: No such file /Users/user/Projects/project_name/{}

nosetests --verbosity 1 ./project_name/backend/tests.py
./project_name/contrib/auth/tests.py
./project_name/frontend/tests.py
 --failed --stop --nocapture --debug=DEBUG --nologcapture
To reuse old database "test_db" for speed, set env var REUSE_DB=1.
To reuse old database "test_db1" for speed, set env var REUSE_DB=1.
Creating test database for alias 'default'...
Creating schema msg
Creating schema dict
Creating test database for alias 'db2'...
Creating schema msg
Creating schema dict
E
======================================================================
ERROR: Failure: OSError (No such file /Users/user/Projects/project_name/{})
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/user/.virtualenvs/project_name/lib/python2.7/site-packages/nose/failure.py", line 39, in runTest
    raise self.exc_class(self.exc_val)
OSError: No such file /Users/user/Projects/project_name/{}

----------------------------------------------------------------------
Ran 1 test in 0.001s

FAILED (errors=1)
Destroying test database for alias 'default'...
Destroying test database for alias 'db2'...

find . -name tests.py -print0 | xargs -0 -Ixxx ./manage.py test xxx --settings=project_name.conf.test.settings