Comment by valzam

That's AI getting an example of replicating the state that shows the bug which is exactly what I'm talking about. It does that far more than humans do, and it's ace. That's how you should be debugging a system - replicate the issue, understand why it breaks in that given state, and then make a code change to fix it.

Sometimes you can do that mentally and fix the code. Often your fix will be right especially in a relatively simple part of the code. However, equally often you'll fix a different problem (or something that wasn't a problem at all), and the original bug will remain but you'll believe you corrected the issue. This is why you should always replicate a bug to understand it, and why you should always add a test whenever you fix a bug to prove you actually fixed it as well as preventing future regressions.