Skipping to merge install phase in Paludis

Don't you hate it when building a lengthy package succeeds, installs all right into the image, only to fail for some trivial reason (like out of disk space) when merging into the filesystem? In portage you could just use the ebuild(1) command to short-circuit it right to merge. It's not that easy with Paludis, unfortunately.

But worry not, undocumented environment variables to the rescue! The SKIP_FUNCTIONS environment variable allows you to force paludis not to execute some phases of the install action. The magic combo is SKIP_FUNCTIONS="init killold setup saveenv unpack compile install". It fails on loadenv just before postrm for some reason (probably because we barred it from saveenv, but there seems to be no way to skip one saveenv and not another), but by that point the package is already merged.

But really, they ought to make it easier to do such tricks (or at least document the freakin' variable). I can only imagine how hard it must be to debug ebuilds with paludis... Or maybe there is something I don't know about?