Make the check for the `message_extractors` setup keyword more robst.

diff --git a/babel/messages/frontend.py b/babel/messages/frontend.py
index 5e7e3879e3a10436d3cb685e70f564bf784e472c..622df2dd80083aa64d115b9d6aa1374e6483329e 100644 (file)
--- a/babel/messages/frontend.py
+++ b/babel/messages/frontend.py
@@ -201,7 +201,7 @@ class extract_messages(Command):
             finally:
                 fileobj.close()
 
-        elif self.distribution.message_extractors:
+        elif getattr(self.distribution, 'message_extractors', None):
             message_extractors = self.distribution.message_extractors
             for dirname, mapping in message_extractors.items():
                 if isinstance(mapping, basestring):