/usr/lib/x86_64-linux-gnu/libclutter-glx-1.0.so.0 is in libclutter-1.0-0 1.16.4-0ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libclutter-1.0.so.0.1600.4
/usr/lib/x86_64-linux-gnu/libclutter-1.0.so.0.1600.4