Technically <arch> should work, but in practice its often a blackhole. Here's an ad-hoc list of contacts that have been helpful in the past.

People to poke for manual builds

If a build is down, or the maintainer is unresponsive, here's a list of people who maybe able to do a by-hand build for you. Please only include developers who have proven themselves able to do clean builds. (I generally include the necessary pbuilder commands in my requests so that the porter can just cut and paste -dannf)