galera.galera_bf_lock_wait: Test failure: wsrep_trans_observer.h:422: mysqld got signal 6

./mtr galera.galera_bf_lock_wait --force --max-test-fail=0 --repeat=3

./mtr --suite galera --force --big-test --max-test-fail=0

galera.galera_bf_lock_wait 'innodb'      [ pass ]  107151

galera.galera_bf_lock_wait 'innodb'      [ 2 fail ]

Completed: Failed 1/3 tests, 66.67% were successful.

mysqltest: At line 50: query 'drop table t1' failed: 2013: Lost connection to MySQL server during query

The result from queries just before the failure was:

< snip >

WHILE 1 DO

start transaction;

update t1 set b=connection_id() where a=1;

commit;

END WHILE;

END|

connect node_1_p1, 127.0.0.1, root, , test, $NODE_MYPORT_1;

call p1;

connect node_1_p2, 127.0.0.1, root, , test, $NODE_MYPORT_1;

call p1;

connect node_2_p1, 127.0.0.1, root, , test, $NODE_MYPORT_2;

call p1;

connect node_2_p2, 127.0.0.1, root, , test, $NODE_MYPORT_2;

call p1;

connection default;

checking error log for 'BF lock wait long' message for 10 times every 10 seconds ...

drop table t1;

mysqld: /home/stepan/galera/git/10.4/server/sql/wsrep_trans_observer.h:422: void wsrep_commit_empty(THD*, bool): Assertion `have_error || !wsrep_current_error(thd)' failed.

190227 12:17:54 [ERROR] mysqld got signal 6 ;

Server version: 10.4.3-MariaDB-debug-log

key_buffer_size=1048576

read_buffer_size=131072

max_used_connections=6

max_threads=153

thread_count=15

It is possible that mysqld could use up to 

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 63481 K  bytes of memory

Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x7f852c000b00

Attempting backtrace. You can use the following information to find out

where mysqld died. If you see no messages after this, something went

terribly wrong...

stack_bottom = 0x7f85a804bd30 thread_stack 0x49000

/home/stepan/galera/git/10.4/server/sql/mysqld(my_print_stacktrace+0x40)[0x559dbb4abc56]

/home/stepan/galera/git/10.4/server/sql/mysqld(handle_fatal_signal+0x3e2)[0x559dbace4625]

sigaction.c:0(__restore_rt)[0x7f85b8d315d0]

:0(__GI_raise)[0x7f85b7020207]

:0(__GI_abort)[0x7f85b70218f8]

:0(__assert_fail_base)[0x7f85b7019026]

:0(__GI___assert_fail)[0x7f85b70190d2]

sql/wsrep_trans_observer.h:423(wsrep_commit_empty(THD*, bool))[0x559dbace69cf]

sql/handler.cc:1681(ha_commit_trans(THD*, bool))[0x559dbacea346]

sql/transaction.cc:313(trans_commit(THD*))[0x559dbab28fa8]

sql/sql_parse.cc:5849(mysql_execute_command(THD*))[0x559dba9ac6ae]

sql/sp_head.cc:3591(sp_instr_stmt::exec_core(THD*, unsigned int*))[0x559dba8c1180]

sql/sp_head.cc:3319(sp_lex_keeper::reset_lex_and_exec_core(THD*, unsigned int*, bool, sp_instr*))[0x559dba8c046e]

sql/sp_head.cc:3497(sp_instr_stmt::execute(THD*, unsigned int*))[0x559dba8c0ccc]

sql/sp_head.cc:1341(sp_head::execute(THD*, bool))[0x559dba8ba7cb]

sql/sp_head.cc:2283(sp_head::execute_procedure(THD*, List<Item>*))[0x559dba8bd1f2]

sql/sql_parse.cc:2959(do_execute_sp(THD*, sp_head*))[0x559dba9a2018]

sql/sql_parse.cc:3201(Sql_cmd_call::execute(THD*))[0x559dba9a2c04]

sql/sql_parse.cc:6330(mysql_execute_command(THD*))[0x559dba9ae55b]

sql/sql_parse.cc:8141(mysql_parse(THD*, char*, unsigned int, Parser_state*, bool, bool))[0x559dba9b3777]

sql/sql_parse.cc:7964(wsrep_mysql_parse(THD*, char*, unsigned int, Parser_state*, bool, bool))[0x559dba9b2da6]

sql/sql_parse.cc:1804(dispatch_command(enum_server_command, THD*, char*, unsigned int, bool, bool))[0x559dba99eb44]

sql/sql_parse.cc:1358(do_command(THD*))[0x559dba99d491]

sql/sql_connect.cc:1399(do_handle_one_connection(CONNECT*))[0x559dbab14180]

sql/sql_connect.cc:1303(handle_one_connection)[0x559dbab13ec4]

perfschema/pfs.cc:1864(pfs_spawn_thread)[0x559dbb443bd1]

pthread_create.c:0(start_thread)[0x7f85b8d29dd5]

/lib64/libc.so.6(clone+0x6d)[0x7f85b70e7ead]

Trying to get some variables.

Some pointers may be invalid and cause the dump to abort.

Query (0x7f852c02f508): commit

Connection ID (thread ID): 29

Status: KILL_QUERY

Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on