Comment 6 for bug 385276

When modifying an existing package, the best practice is to keep whatever patchsystem the Debian packaging is already using. If the Debian package uses direct modification of files , then you should continue to do so.

In the dwdiff case, it doesn't use any patchsystem and you can see by looking at the current .diff.gz that it already modified files outside the debian/ directory. You should do the same.

Anyway, in your debdiff you patched man/dwdiff.1 directly so it's OK. It's just your addition of "quilt" build-dependency that is unnecessary, since you don't even call quilt from your debian/rules and you don't ship any patches in debian/.

Could you please provide a new debdiff without the build dep change (and the related changelog entry) ? Test that it builds and fixes both issues ?