Comment 5 for bug 1242417

build-efi-images references EFI/ubuntu:
"$grub_mkimage" -O "$platform" -o "$outdir/grub$efi_name.efi" \
 -d "$grub_core" -p /EFI/ubuntu $GRUB_MODULES

everything else in the world uses bootloader_id such that EFI/kubuntu gets used:
if [ "$bootloader_id" ] && [ -d "/boot/efi/EFI/$bootloader_id" ]; then

Since the images however reference EFI/ubuntu installations are broken... so I guess the options are
a) create 2 sets of images (one for /ubuntu and for /kubuntu)
b) find a way to make the images generic such that both work
c) change everything else in the world to not use bootloader_id