/usr/share/doc/ecj-gcj/changelog.Debian.gz is in ecj-gcj 3.10.1-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/ecj-gcj/../ecj/changelog.Debian.gz
/usr/share/doc/ecj-gcj/../ecj/changelog.Debian.gz