This file is indexed.

/usr/lib/x86_64-linux-gnu/libOSMesa.so is in libosmesa6-dev 10.3.2-1+deb8u1.

This file is owned by root:root, with mode 0o777.

It is a symlink to /usr/lib/x86_64-linux-gnu/libOSMesa.so.8.0.0