/usr/lib/mysql-testsuite/r/lowercase2.require is in percona-xtradb-cluster-testsuite-5.5 5.5.34-25.9+dfsg-0ubuntu4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | Variable_name Value
lower_case_table_names 2
|