I don't know if GHC provides either, but either a borrowing or a dup feature would handle that (the latter would probably count as "cheat"). There may be other ways as well.

Since linear types are a separate opt-in feature you'd probably need (as far as I understand) you'd need separate printers anyway, so you could probably "cheat" them in. Though I think the sort of structures you'd want to be linear would generally not be amenable to print-debugging anyway.