parts.partition_special_innodb failed in buildbot with timeout

parts.partition_special_innodb 'innodb'  w4 [ fail ]

        Test ended at 2018-07-24 16:31:41

CURRENT_TEST: parts.partition_special_innodb

mysqltest: At line 147: query 'reap' failed: 1205: Lock wait timeout exceeded; try restarting transaction

The result from queries just before the failure was:

< snip >

Table	Op	Msg_type	Msg_text

test.t1	check	status	OK

connection con1;

UNLOCK TABLES;

connection con2;

DROP TABLE t1;

connection con1;

CREATE TABLE t2 ( i INT NOT NULL AUTO_INCREMENT PRIMARY KEY, f INT )

ENGINE = InnoDB PARTITION BY HASH(i) PARTITIONS 2;

connection con2;

SET lock_wait_timeout = 2;

connection con1;

LOCK TABLE t2 READ;

connection con2;

ALTER TABLE t2 ADD PARTITION PARTITIONS 2;

ERROR HY000: Lock wait timeout exceeded; try restarting transaction

ALTER TABLE t2 ADD PARTITION PARTITIONS 2;

connection con1;

UNLOCK TABLES;

connection con2;

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