Removal of kernel images broken if grub is removed but not purged

Binary package hint: grub

I installed grub2, necessarily removing grub, however, I did not yet purge grub, so its config files remain. One of those files is called in the prerm script of kernel image packages, but it fails when grub is not actually installed, causing the removal of kernel images to fail:

run-parts: executing /etc/kernel/prerm.d/last-good-boot
/etc/kernel/prerm.d/last-good-boot: 3: /usr/sbin/kernel-helper: not found
run-parts: /etc/kernel/prerm.d/last-good-boot exited with return code 127
Failed to process /etc/kernel/prerm.d at /var/lib/dpkg/info/linux-image-2.6.28-3-generic.prerm line 267.
dpkg: error processing linux-image-2.6.28-3-generic (--purge):
 subprocess pre-removal script returned error exit status 2

Packages must gracefully handle the situation of them being removed but their config files remaining.

kosh@isis:~$ lsb_release -rd
Description: Ubuntu jaunty (development branch)
Release: 9.04
kosh@isis:~$ dpkg -l grub
[…]
rc grub 0.97-29ubuntu46 GRand Unified Bootloader