innodb.innodb-alter-tempfile failed in buildbot, table already exists

innodb.innodb-alter-tempfile '4k,innodb' w2 [ fail ]

        Test ended at 2018-02-11 13:04:52

CURRENT_TEST: innodb.innodb-alter-tempfile

mysqltest: At line 52: query 'ALTER TABLE t1 ADD PRIMARY KEY (f2, f1)' failed: 1050: Table 'test/#sql-ib19-2734628116' already exists

The result from queries just before the failure was:

< snip >

# temporary tablename.

# Crash the server in ha_innobase::commit_inplace_alter_table()

CREATE TABLE t1 (f1 INT NOT NULL, f2 INT NOT NULL) ENGINE=innodb;

SET debug='d,innodb_alter_commit_crash_before_commit';

Warnings:

Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead

# Write file to make mysql-test-run.pl expect crash

# Execute the statement that causes the crash

ALTER TABLE t1 ADD PRIMARY KEY (f2, f1);

ERROR HY000: Lost connection to MySQL server during query

# Startup the server after the crash

# Read and remember the temporary table name

show create table t1;

Table	Create Table

t1	CREATE TABLE `t1` (

  `f1` int(11) NOT NULL,

  `f2` int(11) NOT NULL

) ENGINE=InnoDB DEFAULT CHARSET=latin1

# Consecutive Alter table does not create same temporary file name

ALTER TABLE t1 ADD PRIMARY KEY (f2, f1);