This file is indexed.

/usr/lib/x86_64-linux-gnu/pkgconfig/lua51.pc is in liblua5.1-0-dev 5.1.5-8ubuntu1.

This file is owned by root:root, with mode 0o777.

It is a symlink to /usr/lib/x86_64-linux-gnu/pkgconfig/lua5.1.pc