Ahh, I see, there's a circular dependency:

localrepo imports extensions imports commands imports bundlerepo imports localrepo.

Without demandload, by the time bundlerepo refers to localrepo, localrepo hasn't
finished filling out its namespace, but is still marked as imported.

With demandload, we don't bother with the other imports until later and
everything works out nicely.

I'll try to fix this, but I'm more interested in the case where demandload breaks.