I used Debian's Multistrap on another computer to make the chroot. I just copied it into it's own directory somewhere on /home and used it from there.

You'll need to enable dev-mode, and you'll probably need to remount the partition it's on without the noexec option. It's a pretty standard chroot from there on.

I can write up the process somewhere or share the filesystem if there's enough interest.

I haven't tried it myself, but http://technoticraccoon.com/post/27876540798/how-to-create-a... looks like it may be the way to go.