Comment 1 for bug 1689988

Easy to make this testcase fail locally with large --repeat. Not sure if the failure cause is the same.

rpl.rpl_stop_slave 'stmt' [ fail ]
        Test ended at 2017-05-11 06:51:18

CURRENT_TEST: rpl.rpl_stop_slave
mysqltest: In included file "./include/diff_tables.inc":
included from ./include/diff_tables.inc at line 192:
included from ./extra/rpl_tests/rpl_stop_slave.test at line 61:
At line 192: command "diff_files" failed with error 2. my_errno=175
...
include/diff_tables.inc [master:t1, slave:t1]
--- /Users/laurynas/percona/obj-percona-5.6-debug/mysql-test/var/mysqld.1/data//diff_table-master-test-t1 2017-05-11 06:51:18.000000000 +0300
+++ /Users/laurynas/percona/obj-percona-5.6-debug/mysql-test/var/mysqld.2/data//diff_table-slave-test-t1 2017-05-11 06:51:18.000000000 +0300
@@ -1 +0,0 @@
-1
safe_process[46070]: Child process: 46071, exit: 1