This is intended behavior for debhelper. I think you'd want to reach out to the Foundations team likely through https://discourse.ubuntu.com/ if there is a reason you need to build udeb's for Ubuntu.
** Changed in: debhelper (Ubuntu) Status: Confirmed => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1965984 Title: Cannot build udeb with debhelper 13.6ubuntu1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/debhelper/+bug/1965984/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs