/usr/lib/x86_64-linux-gnu/libsquirrel3.so is in libsquirrel-dev 3.1-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libsquirrel3.so.0
/usr/lib/x86_64-linux-gnu/libsquirrel3.so.0