The handling of reply document parse errors in mongoc_server_description_handle_hello () leads to absent or misleading error messages. Generally, it is preferred to set the domain, code, and message properties of the server description's error member when a failure is encountered. However, in most instances when a failure (parse error) is encountered in mongoc_server_description_handle_hello () no error properties are set and the operation simply terminates. It would be better to set the relevant properties to ensure that sensible error messages are produced in the event of a failure.