/usr/lib/x86_64-linux-gnu/libReviewboardHelpers.so.5 is in libkf5purpose-bin 5.44.0-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libReviewboardHelpers.so.5.44.0
/usr/lib/x86_64-linux-gnu/libReviewboardHelpers.so.5.44.0