Index: django/db/models/query.py
===================================================================
--- django/db/models/query.py   (revision 4460)
+++ django/db/models/query.py   (working copy)
@@ -568,7 +568,7 @@
         try:
             select, sql, params = self._get_sql_clause()
         except EmptyResultSet:
-            raise StopIteration
+            raise []
         
         sql = 'SELECT %s %s GROUP BY 1 ORDER BY 1 %s' % \
             (backend.get_date_trunc_sql(self._kind, '%s.%s' % (backend.quote_name(self.model._meta.db_table),