maria.insert_select failed in buildbot with timeout

maria.insert_select                      w1 [ fail ]  timeout after 900 seconds

        Test ended at 2018-02-10 21:00:35

Test case timeout after 900 seconds

== /dev/shm/var/1/log/insert_select.log == 

create table t1 (pk int primary key) engine=Aria;

insert into t1 values (1);

insert into t1 select sleep(2)+1 from t1;

insert into t1 select 2 from t1;

 == /dev/shm/var/1/tmp/analyze-timeout-mysqld.1.err ==

mysqltest: Could not open connection 'default' after 500 attempts: 2002 Can't connect to local MySQL server through socket '/dev/shm/var/tmp/1/mysqld.1.sock' (111 "Connection refused")