/usr/share/doc/libnetcdf-cxx-legacy-dev/changelog.Debian.gz is in libnetcdf-cxx-legacy-dev 4.2-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libnetcdf-cxx-legacy-dev/../libnetcdf-c++4/changelog.Debian.gz