/usr/share/doc/libapache2-mod-shib2/changelog.Debian.gz is in libapache2-mod-shib2 2.4.3+dfsg-2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libapache2-mod-shib2/../libshibsp5/changelog.Debian.gz