/usr/lib/x86_64-linux-gnu/libmirprotobuf.so is in libmirprotobuf-dev 0.1.8+14.04.20140411-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmirprotobuf.so.0
/usr/lib/x86_64-linux-gnu/libmirprotobuf.so.0