/usr/lib/x86_64-linux-gnu/libflatzebra-0.1.so is in libflatzebra-dev 0.1.6-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libflatzebra-0.1.so.2.0.0
/usr/lib/x86_64-linux-gnu/libflatzebra-0.1.so.2.0.0