Yes, this dropped from my radar completely. The dependency chain change required us to make installer-related changes (in both grub-installer and ubiquity) that made sure the right packages aren't purged from the system. But what I did miss is adding the new deps to the grub2-signed package in case someone would be pulling in the new grub packages from the archive during installation.
So actually the bug here is that *old* images are failing to install on UEFI systems when automatic download of updates is switched on. This is why it was not noticed - I only tested the changes on both the dailies for bionic and cosmic.
Yes, this dropped from my radar completely. The dependency chain change required us to make installer-related changes (in both grub-installer and ubiquity) that made sure the right packages aren't purged from the system. But what I did miss is adding the new deps to the grub2-signed package in case someone would be pulling in the new grub packages from the archive during installation.
So actually the bug here is that *old* images are failing to install on UEFI systems when automatic download of updates is switched on. This is why it was not noticed - I only tested the changes on both the dailies for bionic and cosmic.