vpslab/debootstrap-cookbook — pull request #2 by mlomnicki (2012-12-10 03:05:06+00:00)
Title: Don't cache files in /tmp.

Most often /tmp has the nosuid bit set hence
debootstraped files like ping or sudo which need
to be suid-ed are invalid.

/var/cache seems to be the best choice to cache files created by debootstrap.