CONNECT VIR tables return inconsistent error for UPDATE

MariaDB [test]> CREATE OR REPLACE TABLE numbers

    ->     ENGINE = CONNECT,

    ->     TABLE_TYPE = VIR,

    ->     BLOCK_SIZE = 3

    -> ;

Query OK, 0 rows affected (0.005 sec)

MariaDB [test]> TRUNCATE TABLE numbers;

ERROR 1296 (HY000): Got error 174 'Virtual tables are read only' from CONNECT

MariaDB [test]> DELETE FROM numbers WHERE n = 1;

ERROR 1296 (HY000): Got error 174 'Virtual tables are read only' from CONNECT

MariaDB [test]> INSERT INTO numbers (n) VALUES (1);

ERROR 1296 (HY000): Got error 174 'Virtual tables are read only' from CONNECT

MariaDB [test]> UPDATE numbers SET n = 10 WHERE n = 1;

ERROR 1296 (HY000): Got error 174 'Table numbers invalid for update' from CONNECT