it's just a matter of consistency: very basically, the examples mention grub-bootloader. With the default image type (efi-raw), it's been working perfectly for years (maybe by chance, but in any case it seemed to be a compatible combination). The recent change means that it no longer works :-). What's more, the error message isn't very explicit, and doesn't point to a configuration error but to what may appear to be a recently-introduced bug. Switching to grub-efi-bootloader allows you to build the image (and start it).
I don't know if it's simply possible to have a consistency check between the image type and the bootloader used: "Bootloader probably not compatible with image type, please use grub-efi-bootloader".
Maybe just change the doc to include grub-efi-bootloader in the examples. Or indeed have a format that remains compatible with MBR partitioning and the appropriate grub.
-- Yann
smime.p7s
Description: Signature cryptographique S/MIME
