/usr/share/doc/libngraph0-dev/changelog.Debian.gz is in libngraph0-dev 6.07.02-2build3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libngraph0-dev/../libngraph0/changelog.Debian.gz
/usr/share/doc/libngraph0-dev/../libngraph0/changelog.Debian.gz