/usr/lib/mysql-testsuite/t/mysql_embedded-master.opt is in percona-server-test-5.6 5.6.22-rel71.0-0ubuntu4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | --default-storage-engine=MyISAM
--default-tmp-storage-engine=MyISAM
--skip-innodb
--server-id=0
|