/usr/share/doc/libchamplain-gtk-0.12-dev/changelog.Debian.gz is in libchamplain-gtk-0.12-dev 0.12.2-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libchamplain-gtk-0.12-dev/../libchamplain-0.12-0/changelog.Debian.gz