/usr/lib/mysql-testsuite/mysql-test-run is in mysql-testsuite-5.6 5.6.16-1~exp1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/mysql-testsuite/mysql-test-run.pl
/usr/lib/mysql-testsuite/mysql-test-run.pl