rpl.rpl_semi_sync_event fails sporadically. This is an upstream problem which was fixed here: http://lists.mysql.com/commits/133904 but I don't see that fix in 5.5.11.
Symptoms:
rpl.rpl_semi_sync_event 'mix' [ exp-fail ] Found warnings/errors in server log file!
Test ended at 2011-04-10 02:52:44
line
110410 12:52:33 [Warning] Slave SQL: Request to stop slave SQL Thread received while applying a group that has non-transactional changes; waiting for completion of the group ... , Error_code: 0
110410 12:52:33 [Warning] Slave SQL: Request to stop slave SQL Thread received while applying a group that has non-transactional changes; waiting for completion of the group ... , Error_code: 0
110410 12:52:33 [Warning] Slave SQL: Request to stop slave SQL Thread received while applying a group that has non-transactional changes; waiting for completion of the group ... , Error_code: 0
^ Found warnings in /home/alexey.kopytov/src/percona/5.5.11/Percona-Server-debug/mysql-test/var/log/mysqld.2.err
ok
Already fixed in mysql 5.5.11