innodb.innodb-change-buffer-recovery failed in buildbot with Lost connection to MySQL server during query

innodb.innodb-change-buffer-recovery 'innodb' w1 [ fail ]

        Test ended at 2019-03-25 10:37:59

CURRENT_TEST: innodb.innodb-change-buffer-recovery

Server [mysqld.1 - pid: 32078, winpid: 32078, exit: 256] failed during test run

Server log from this test:

----------SERVER LOG START-----------

2019-03-25 10:37:46 140647838673024 [Note] /usr/sbin/mysqld (mysqld 10.2.23-MariaDB-debug-log) starting as process 31905 ...

2019-03-25 10:37:46 140647838673024 [Warning] Could not increase number of max_open_files to more than 1024 (request: 4186)

2019-03-25 10:37:46 140647838673024 [Warning] Changed limits: max_open_files: 1024  max_connections: 151 (was 151)  table_cache: 421 (was 2000)

2019-03-25 10:37:54 140138950858880 [Note] /usr/sbin/mysqld (mysqld 10.2.23-MariaDB-debug-log) starting as process 32079 ...

2019-03-25 10:37:54 140138950858880 [Warning] Could not increase number of max_open_files to more than 1024 (request: 4186)

2019-03-25 10:37:54 140138950858880 [Warning] Changed limits: max_open_files: 1024  max_connections: 151 (was 151)  table_cache: 421 (was 2000)

----------SERVER LOG END-------------

mysqltest failed but provided no output

The result from queries just before the failure was:

< snip >

INSERT INTO t1 SELECT 0,b,c FROM t1;

INSERT INTO t1 SELECT 0,b,c FROM t1;

INSERT INTO t1 SELECT 0,b,c FROM t1;

INSERT INTO t1 SELECT 0,b,c FROM t1;

BEGIN;

SELECT b FROM t1 LIMIT 3;

b

x

x

x

connect  con1,localhost,root,,;

BEGIN;

DELETE FROM t1 WHERE a=1;

INSERT INTO t1 VALUES(1,'X',1);

SET DEBUG_DBUG='+d,crash_after_log_ibuf_upd_inplace';

SELECT b FROM t1 LIMIT 3;

ERROR HY000: Lost connection to MySQL server during query

disconnect con1;

connection default;

FOUND 1 /Wrote log record for ibuf update in place operation/ in my_restart.err

 - found 'core.32079' (0/0)

Trying 'dbx' to get a backtrace

gdb not found, cannot get the stack trace