Comment 1 for bug 1695666

From the POV of "u-r-u shouldn't be a dumping ground for quirking upgrade issues we can fix in packages", shouldn't this check be in preinsts for the packages that twiddle /boot/efi, not in the upgrader?

Also, can we do better here (like we do with non-mounted bootloader partitions, like PReP) and somehow automatically detect the correct partition and mount it before attempting to use it?