gcol.gcol_rollback failed in buildbot with Unknown storage engine 'InnoDB'

gcol.gcol_rollback 'innodb'              w3 [ fail ]

        Test ended at 2018-08-10 17:22:44

CURRENT_TEST: gcol.gcol_rollback

mysqltest: At line 36: query 'SELECT * FROM t' failed: 1286: Unknown storage engine 'InnoDB'

The result from queries just before the failure was:

< snip >

DELETE FROM t where a = 12;

ROLLBACK TO SAVEPOINT a;

COMMIT;

CHECK TABLE t;

Table	Op	Msg_type	Msg_text

test.t	check	status	OK

SELECT * FROM t;

a	b

9	9

BEGIN;

INSERT INTO t (a) VALUES (10);

SELECT * FROM t;