How to perform a nested mount when using chroot?

Note that this question is prompted by the circumstances detailed by me (as Xl1NntniNH7F) in http://www.linuxquestions.org/questions/linux-desktop-74/boot-failure-upon-updating-e2fsprogs-in-ubuntu-10-10-a-947328/. Thus if you could address the underlying cause of the boot failure, I would very much appreciate it.

I'm trying to replicate the environment in my ubuntu installation (where the home folder is on a separate partition) in order to run make uninstall. I'm using a live cd.

How to mount a dir in one partition into a directory on another mounted partition? I did chroot /mnt/sda2 but I don't know how to mount sda3 to /home, and my various attempts didn't work. As I am unfamiliar with chroot, my approach could be wrong, so it would be great if you could suggest what I should do, given my circumstances.

-

For example, I have /dev set up as a tmpfs with mdev and /dev/pts mounted as a devpts filesystem:
$mount | grep /dev devpts /dev/pts devpts rw 0 0 mdev /dev tmpfs rw,nosuid 0 0  Then in my script I do: d=/mnt/chroot for m in dev dev/pts ; do grep -sq$d/$m /proc/mounts || mount --bind /$m $d/$m

With the current SVN Busybox trunk, it seems /dev is mounted twice at /mnt/chroot/dev and /mnt/chroot/dev/pts instead of /dev at /mnt/chroot/dev and /dev/pts at /mnt/chroot/dev/pts