make emits errors when it can't find dependency files even though it knows how
to generate them perfectly well on its own.  This is irritating because vi's
quickfix picks up on these errors after :make and then tries to help the user
along in "fixing" them, even though they're really not errors at all.  Yeah,
maybe this is a make bug (annoyance, really), but I still want to find a way
around it.