Ok, this finally seems to be working. I ran a bionic livefs ubuntu-core build with -proposed enabled and now I can confirm that the build pulled in the core18 assertion and built a core18 image in the end:
https://launchpadlibrarian.net/451484208 /buildlog_ubuntu_bionic_amd64_ubuntu-core_BUILDING.txt.gz (as seen in the logs, livecd-rootfs 2.525.35 was used) ** Tags removed: verification-needed verification-needed-bionic ** Tags added: verification-done verification-done-bionic -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1852332 Title: Bionic builds can't build core18 images To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1852332/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs