tokudb_bugs.xa failed in buildbot with lock wait timeout

tokudb_bugs.xa                           w1 [ fail ]

        Test ended at 2017-01-09 04:10:19

CURRENT_TEST: tokudb_bugs.xa

mysqltest: At line 204: query 'UPDATE t1 SET a=5 WHERE a=1' failed with wrong errno 1205: 'Lock wait timeout exceeded; try restarting transaction', instead of 1213...

The result from queries just before the failure was:

< snip >

xa rollback 'a';

xa start 'a';

xa end 'a';

xa rollback 'a';

xa start 'a';

xa end 'a';

xa prepare 'a';

xa commit 'a';

xa start 'a';

xa end 'a';

xa prepare 'a';

xa commit 'a';

CREATE TABLE t1(a INT, KEY(a)) ENGINE=TokuDB;

INSERT INTO t1 VALUES(1),(2);

BEGIN;

UPDATE t1 SET a=3 WHERE a=1;

BEGIN;

UPDATE t1 SET a=4 WHERE a=2;

UPDATE t1 SET a=5 WHERE a=2;

UPDATE t1 SET a=5 WHERE a=1;