Bug#990497: grub-efi-amd64: grub-install not run if /boot/efi/EFI/debian doesn't exist

[Yves-Alexis Perez]

Package: grub-efi-amd64
Version: 2.02+dfsg1-20+deb10u4
Severity: normal

Hi,
reporting a bug after an IRC debugging session today.

On a amd64 EFI platform (Buster) I wanted to put the ESP partition on a RAID1
volume, so I recreated the whole thing (RAID1 creation and mkfs.vfat on
the /dev/md1 device), ending with an empty vfat partition.

I then proceeded to dpkg-reconfigure grub-efi-amd64 and chose to force
installation to the removable path (EFI/boot/bootx64.efi) and not to
update NVRAM variables.

After that, grub-install was *not* ran and thus nothing appeared in
/boot/efi/.

Looking at the postinst script, I noticed:

693       grub-efi-ia32|grub-efi-amd64|grub-efi-ia64|grub-efi-arm|grub-efi-arm64)
694         bootloader_id="$(config_item GRUB_DISTRIBUTOR | tr A-Z a-z | \
695                          cut -d' ' -f1)"
696         case $bootloader_id in
697           kubuntu) bootloader_id=ubuntu ;;
698         esac
699         if [ "$bootloader_id" ] && [ -d "/boot/efi/EFI/$bootloader_id" ]; then
700           case grub-efi-amd64 in
701             grub-efi-ia32)  target=i386-efi ;;
702             grub-efi-amd64) target=x86_64-efi ;;
703             grub-efi-ia64)  target=ia64-efi ;;
704             grub-efi-arm)   target=arm-efi ;;
705             grub-efi-arm64) target=arm64-efi ;;
706           esac
707           db_get grub2/force_efi_extra_removable
708           if [ "$RET" = true ]; then
709             FORCE_EXTRA_REMOVABLE="--force-extra-removable"
710           fi
711           NO_NVRAM="$(no_nvram_arg)"
712           run_grub_install --target="$target" "$FORCE_EXTRA_REMOVABLE" "$NO_NVRAM"
713         fi

On Debian GRUB_DISTRIBUTOR is set to `debian` so if /boot/efi/EFI/debian
doesn't exist, then grub-install won't be run at all.

It looks like a bug to me, but maybe I missed something.

Regards,
-- 
Yves-Alexis