Use --print-target-path only as last resort.

Use --print-target-path only as last resort.

--print-target-path may return a path with (escaped) spaces. We'll use that path with $(wildcard ...), that's fine. But then we use the outcome with $(foreach ...) and there things fail badly and there's nothing to do about it.

Therefore we a) try to avoid --print-target-path in the first place and b) explicitly bail out if we end up with spaces.