I've found both various ChatGPT and Claude to be pretty good at finding unknown bugs, but you need a somewhat hefty prompt. Personally I use a prompt that goes

I've found both various ChatGPT and Claude to be pretty good at finding unknown bugs, but you need a somewhat hefty prompt. Personally I use a prompt that goes something like this (shortened here): "Go through all the code below and analyze everything it's doing step-by-step. Then try to explain the overall purpose of the code based on your analysis. Then think through all the edge-cases and tradeoffs based on the purpose, and finally go through the code again and see if you can spot anything weird" Basically, I tried to think of what I do when I try to spot bugs in code, then I just wrote a reusable prompt that basically repeats my own process.