Alter table not returning engine errors

If HA_ERR_GENERIC error is returned from the storage engine during an alter table, I would expect that mariadb call into the storage engines error handler to get the error message.

handler.cpp:3539

   temporary= get_error_message(error, &str);

However alter does not do that. When alter fails (in my case it is because i am running in a clustered environment with ScaleDB and the table is in use on another node) i am getting the following error

mysql> alter table lockwt1 add column c2_3 int;

ERROR 1015 (HY000): Can't lock file (errno: 168 "Unknown (generic) error from engine")

If mariadb called into the engine, a more accurate error would get returned "Table in use on another node"