Comment 1 for bug 127572

I'd like to add that the Software Sources tool registers all the custom archive mirror entries as 3rd-party repositories, and also that the dist-upgrader utility fails spectacularly at using a custom mirror for upgrades. This is especially troublesome in the case of name-based VirtualHosts, because then a /etc/hosts entry to redirect archive.ubuntu.com to the specific server would not be enough to cover it.