A fork is a copy that is maintained separately, and that is exactly what is happening here. You're actually quite right that, if all they were maintaining was a

A fork is a copy that is maintained separately, and that is exactly what is happening here. You're actually quite right that, if all they were maintaining was a Debian package, they could theoretically maintain a source package with a vanilla orig tarball and keep their changes to patches, but that's not what they're doing here: > The support offering will include Blender LTS releases across Linux distributions, Microsoft Windows, and macOS. They're not using quilt to do this. They're using git. At least, that's how I did it when I did it for Canonical.