/usr/lib/x86_64-linux-gnu/libmsgpackc.so is in libmsgpack-dev 1.4.2-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmsgpackc.so.2.0.0
/usr/lib/x86_64-linux-gnu/libmsgpackc.so.2.0.0