rpl.rpl_heartbeat_basic failed in bb

rpl.rpl_heartbeat_basic 'mix'            w4 [ fail ]

        Test ended at 2021-05-29 13:49:55

CURRENT_TEST: rpl.rpl_heartbeat_basic

mysqltest: In included file "./include/end_include_file.inc": 

included from ./include/wait_for_slave_sql_to_start.inc at line 38:

included from ./include/wait_for_slave_to_start.inc at line 27:

included from ./include/start_slave.inc at line 35:

included from /usr/share/mysql/mysql-test/suite/rpl/t/rpl_heartbeat_basic.test at line 269:

At line 55: Found line beginning with --  that didn't contain a valid mysqltest command, check your syntax or use # if you intended to write a comment

The result from queries just before the failure was:

< snip >

CHANGE MASTER TO MASTER_HOST='127.0.0.1', MASTER_PORT=MASTER_PORT, MASTER_USER='root', MASTER_CONNECT_RETRY=20, MASTER_HEARTBEAT_PERIOD='123abc';

ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ''123abc'' at line 1

RESET SLAVE;

CHANGE MASTER TO MASTER_HOST='127.0.0.1', MASTER_PORT=MASTER_PORT, MASTER_USER='root', MASTER_CONNECT_RETRY=20, MASTER_HEARTBEAT_PERIOD='';

ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '''' at line 1

RESET SLAVE;

*** Running slave ***

CHANGE MASTER TO MASTER_HOST='127.0.0.1', MASTER_PORT=MASTER_PORT, MASTER_USER='root', MASTER_CONNECT_RETRY=20, MASTER_HEARTBEAT_PERIOD=0.1;

include/start_slave.inc

connection master;

connection slave;

Heartbeat event received

*** Stopped slave ***

include/stop_slave.inc

Number of received heartbeat events while slave stopped: 0

*** Started slave ***

include/start_slave.inc

More results from queries before failure can be found in /dev/shm/var/4/log/rpl_heartbeat_basic.log