/usr/lib/x86_64-linux-gnu/liblua5.1.so is in liblua5.1-0-dev 5.1.4-12ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/liblua5.1.so.0.0.0
/usr/lib/x86_64-linux-gnu/liblua5.1.so.0.0.0