In (info "(make) Concept Index"), these three items, * :: rules (double-colon): Double-Colon. (line 6) * ::=: Flavors. (line 56) * ::= <1>: Setting. (line 6) just jump to the first page of the make Info manual when one hits RET on them. The first one should jump to (info "(make) Double-Colon") etc. And indeed, they don't even have the hyperlinked color. (Hmm, I might have reported this years ago.) (Or, add "don't click me" warnings on them.)
P.S., (info "(make) Double-Colon") needs at least one example on it.