/usr/lib/x86_64-linux-gnu/libgailutil-3.so is in libgail-3-dev 3.10.8-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libgailutil-3.so.0.0.0
/usr/lib/x86_64-linux-gnu/libgailutil-3.so.0.0.0