I can confirm that the proposed package fixes the problem I reported (with sample ubuntu-minimal_1.412_amd64.deb being from bionic's repositories):
$ dpkg-deb -W ./ubuntu-minimal_1.412_amd64.deb ubuntu-minimal 1.412 $ lsb_release -rd Description: Ubuntu 14.04.5 LTS Release: 14.04 $ apt-cache policy dpkg dpkg: Installed: 1.17.5ubuntu5.8 Candidate: 1.17.5ubuntu5.8 Version table: *** 1.17.5ubuntu5.8 0 100 /var/lib/dpkg/status 1.17.5ubuntu5.7 0 500 http://archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages 1.17.5ubuntu5.6 0 500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages 1.17.5ubuntu5 0 500 http://archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1730627 Title: xz compressed control.tar files not supported To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/dpkg/+bug/1730627/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs