/usr/lib/x86_64-linux-gnu/libcucul++.so is in libcaca-dev 0.99.beta17-2.1ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libcaca++.so
/usr/lib/x86_64-linux-gnu/libcaca++.so