I’m going to need a bigger puncture repair kit

It may be hard to tell in this picture, but that’s a huge tear in the inner tube. I guess that after fixing a small puncture I put the tube back in so it was nipped between tyre and rim. It must have held for a while before finally giving way.
Because this is my newest bike, and a type I’ve never before owned, I don’t have any spare inner tubes lying around. I’ll pick one up on the way into town.