----> 1 SearchQuerySet().models(UserRequestWorkedHistory).filter(user_id=6786786).count()

~/.pyenv/versions/3.6.4/envs/proj/lib/python3.6/site-packages/haystack/query.py in count(self)
520 def count(self):
521 """Returns the total number of matching results."""
--> 522 return len(self)
523
524 def best_match(self):

~/.pyenv/versions/3.6.4/envs/proj/lib/python3.6/site-packages/haystack/query.py in __len__(self)
84 def __len__(self):
85 if self._result_count is None:
---> 86 self._result_count = self.query.get_count()
87
88 # Some backends give weird, false-y values here. Convert to zero.

~/.pyenv/versions/3.6.4/envs/proj/lib/python3.6/site-packages/haystack/backends/__init__.py in get_count(self)
617 self.run_raw()
618 else:
--> 619 self.run()
620
621 return self._hit_count

~/.pyenv/versions/3.6.4/envs/proj/lib/python3.6/site-packages/haystack/backends/__init__.py in run(self, spelling_query, **kwargs)
554 search_kwargs.update(kwargs)
555
--> 556 results = self.backend.search(final_query, **search_kwargs)
557 self._results = results.get('results', [])
558 self._hit_count = results.get('hits', 0)

~/.pyenv/versions/3.6.4/envs/proj/lib/python3.6/site-packages/haystack/backends/__init__.py in wrapper(obj, query_string, *args, **kwargs)
31
32 try:
---> 33 return func(obj, query_string, *args, **kwargs)
34 finally:
35 stop = time()

~/.pyenv/versions/3.6.4/envs/proj/lib/python3.6/site-packages/haystack/backends/simple_backend.py in search(self, query_string, **kwargs)
77 queries.append(Q(**{'%s__icontains' % field.name: term}))
78
---> 79 qs = model.objects.filter(six.moves.reduce(lambda x, y: x | y, queries))
80
81 hits += len(qs)

TypeError: reduce() of empty sequence with no initial value