/usr/share/doc/libisal-dev/changelog.Debian.gz is in libisal-dev 2.21.0-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libisal-dev/../libisal2/changelog.Debian.gz
/usr/share/doc/libisal-dev/../libisal2/changelog.Debian.gz