The Debian diff of this non-native package appears to be completely empty. This usually indicates a mistake when generating the upstream tarball, or it may mean that this was intended to be a native package and was built non-native by mistake.
If the Debian packaging is maintained in conjunction with upstream, this may be intentional, but it's not recommended best practice. If the software is only for Debian, it should be a native package; otherwise, it's better to omit the debian directory from upstream releases and add it in the Debian diff. Otherwise, it can cause problems for some package updates in Debian (files can't be removed from the debian directory via the diff, for example).