/usr/lib/x86_64-linux-gnu/libgdamm-5.0.so is in libgdamm5.0-dev 4.99.11-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libgdamm-5.0.so.13.0.0
/usr/lib/x86_64-linux-gnu/libgdamm-5.0.so.13.0.0