encryption.innodb_first_page fails sporadically in buildbot

encryption.innodb_first_page 'cbc,xtradb' w3 [ fail ]

        Test ended at 2015-07-17 00:11:52

CURRENT_TEST: encryption.innodb_first_page

mysqltest: At line 26: query 'create table t1 (a int)' failed: 2002: Can't connect to local MySQL server through socket '/usr/local/mariadb-10.1.6-linux-x86_64/mysql-test/var/tmp/3/mysqld.1.sock' (2 "No such file or directory")

The result from queries just before the failure was:

call mtr.add_suppression("InnoDB: New log files created, LSN");

call mtr.add_suppression("InnoDB: Creating foreign key constraint system tables");

shutdown;

create table t1 (a int);

 - saving '/usr/local/mariadb-10.1.6-linux-x86_64/mysql-test/var/3/log/encryption.innodb_first_page-cbc,xtradb/' to '/usr/local/mariadb-10.1.6-linux-x86_64/mysql-test/var/log/encryption.innodb_first_page-cbc,xtradb/'