Comment 4 for bug 1008225

It looks to me like the issue is that while vmbuilder moves away initctl to avoid starting any services, upstart (or maybe another init?) gets reinstalled, replacing the moved initctl. As a result, it leaks a cron invocation. (I'm not totally sure why the policy-rc.d change that's in the guest isn't working --- my assumption is that initctl is contacting Upstart outside the chroot over D-Bus, and that Upstart sees the hosts' /usr/sbin/policy-rc.d. I guess vmbuilder could stash something in that policy-rc.d, but that seems slightly messy.)

I've attached a patch that seems to allow me to build VMs running hardy, lucid, maverick, natty, oneiric, and precise (all amd64; I haven't tested other architectures). The earlier suites are no longer supported, so building those bails pretty quickly...