Bug#284930: grub install does not work if /boot/grub is on a separate partition

[Thomas Hofer <th@monochrom.at>]

Package: debian-installer
Version: Sarge netinst RC2

I'd like to use a separate partition for /boot/grub, because I have a 
heavy multiboot configuration and I don't like to lose my menu.lst when 
I reinstall the "master" OS.

The problem is that the installer can't handle this situation. I 
partitioned /boot/grub on hda5 and the root fs on hda6, swap is on 
hda7. The installation of grub fails and on console #3 there is an 
error, saying that there is no /boot/grub on hda6 and that I have to 
use the --root-directory= parameter.

I chrooted /target and started grub-install manually. I got the same 
error as before. 

Using "grub-install --root-directory=/boot/grub /dev/hda" grub installs 
without error, but the directory structure looks not as I intended. The 
files are installed into /boot/grub/boot/grub. I think that the wrong 
path could be fixed on the grub shell using the "prefix" parameter of 
the setup command (leave it empty). But grub-install does not provide 
such an parameter.

Conclusion: I guess two things are missing:

First, grub-install needs a parameter to override the default prefix 
"/boot/grub".

Second, debian-installer has to recognize that /boot/grub is on another 
partition and must therefore supply grub-install with additional 
information. This imaginary call might have worked:

grub-install --root-directory=/boot/grub prefix= /dev/hda