Bug#746662: add install-time option to place grub-efi in removable media path
I agree with the original poster and argue for increasing the priority
of this bug, because under certain circumstances it may make a Debian
system appear to be unbootable.
As it stands, if something causes the computer's EFI NVRAM to get wiped
(e.g., user error, firmware bug, firmware upgrade), many computers will
appear to be unbootable because their EFI implementations provide no way
to scan for non-default bootloaders in the EFI System Partition. For a
technically-oriented user, a boot disc such as rEFInd can be used to fix
this, but less-savvy users will simply think that Debian broke.
For reference, the default bootloader exists in the EFI System Partition
at \EFI\BOOT\bootx64.efi (/boot/efi/EFI/BOOT/bootx64.efi as mounted in
Debian) on a x86-64 architecture machine [UEFI Specification Version 2.4
(Errata B) Section 3.4.1]. If no NVRAM bootloader entries are applicable
on a computer, the system will boot from the first default bootloader it
finds on the first ESP partition it finds.
To increase robustness of installations against firmware issues, the
Debian installer should prompt the user to install a copy of the
bootloader into the default bootloader location of the ESP. I would
recommend that the default value of this prompt be Yes if no default
bootloader currently exists, and No if one currently exists (along with
the requisite warning about overwriting).