An eBay listing of a debug version of Ocarina of Time has recently surfaced, claiming to be from the testing phases of the game's Gamecube rerelease.
The seller lists a few details about the mysterious cart, saying it will only work with an expansion pak installed, but otherwise works fine on a retail N64, and that if, of course, includes a debug menu.
The seller also provided a video of the cart in use, which I've embedded below.
I know I'd love to own a piece of Zelda history like this, but this is a bit steep for a rather unremarkable period in the series' history (being that the cart is for a rerelease and not the original 1998 version). But that might just be the jealousy talking, I might be singing a different tune if I had that £100,000 in the cushions of my couch.