For the roundcube packages I wrote about before, I needed a lenny build system. I did not want to load the required packages to the production server. I used to use debootstrap for this but I wanted to keep a clean base system without copying around all the time.

After a bit of searching, I stumbled across schroot, which turned out to be a really useful package. The blog post “Joys of Schroot” by Enrico had me going in no time (thanks Enrico!).

Since I built a number of packages multiple times, I did not want to download the required dependencies each time. I also did not want to do any tricks with approx as suggested by Enrico. Instead, I added another bind-mount to /etc/schroot/mount-defaults:

/var/cache/apt/archives	/var/cache/apt/archives		none	rw,bind		0	0

With this simple change, the chroots now share the apt cache with my main system.