**Reported in Launchpad by Laurynas Biveinis last update 02-09-2016 08:35:21

On 5.5 trunk:

MTR's internal check of the test case 'rpl.rpl_init_slave' failed.
This means that the test case does not preserve the state that existed
before the test case was executed. Most likely the test case did not
do a proper clean-up. It could also be caused by the previous test run
by this thread, if the server wasn't restarted.
This is the diff of the states of the servers before and after the
test case was executed:
mysqltest: Logging to '/mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/ubuntu-xenial-64bit/mysql-test/var/4/tmp/check-mysqld_2.log'.
mysqltest: Results saved in '/mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/ubuntu-xenial-64bit/mysql-test/var/4/tmp/check-mysqld_2.result'.
mysqltest: Connecting to server localhost:13022 (socket /tmp/V28HcbxC0d/4/mysqld.2.sock) as 'root', connection 'default', attempt 0 ...
mysqltest: ... Connected.
mysqltest: Start processing test commands from './include/check-testcase.test' ...
mysqltest: ... Done processing test commands.
— /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/ubuntu-xenial-64bit/mysql-test/var/4/tmp/check-mysqld_2.result 2016-08-31 17:14:30.586896830 +0300
+++ /mnt/workspace/percona-server-5.5-trunk/BUILD_TYPE/debug/Host/ubuntu-xenial-64bit/mysql-test/var/4/tmp/check-mysqld_2.reject 2016-08-31 17:14:31.009883304 +0300
@@ -268,7 +268,7 @@
MAX_BINLOG_FILES 0
MAX_BINLOG_SIZE 1073741824
MAX_BINLOG_STMT_CACHE_SIZE 18446744073709547520
-MAX_CONNECTIONS 151
+MAX_CONNECTIONS 500
MAX_CONNECT_ERRORS 10
MAX_DELAYED_THREADS 20
MAX_ERROR_COUNT 64

mysqltest: Result content mismatch

This is caused by the slave SQL thread racing to execute init-slave with the testcase, and no synchronisation between the two.