/usr/lib/pyshared/python2.7/rdiff_backup/_librsync.so is in rdiff-backup 1.2.8-7.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/pyshared/python2.7/rdiff_backup/../../../python2.7/dist-packages/rdiff_backup/_librsync.so