Logging exc_info with unicode breaks

celery/worker/job.py

@@ -513,7 +513,7 @@ class TaskRequest(object):
 
         log_with_extra(self.logger, logging.ERROR,
                        self.error_msg.strip() % context,
-                       exc_info=exc_info,
+                       #exc_info=exc_info,
                        extra={"data": {"hostname": self.hostname,
                                        "id": self.task_id,
                                        "name": self.task_name}})