The host delivers its own successor as an archive whose target is a new
directory each version, and since mesh-host 63 the record keeps a resource's
former target for the next apply to remove. An archive has no removal (issue
162), so the first host that replaced itself under that rule refused its own
former version at the first step of every apply, and all four machines applied
nothing from then on. A former target nobody dropped is forgotten and said;
an archive the declaration dropped still refuses.