Let's say you don't have the time to give it the complete understand-and-write-unit-test-suite approach though. How are you verifying you fixed the bug otherwi

Let's say you don't have the time to give it the complete understand-and-write-unit-test-suite approach though. How are you verifying you fixed the bug otherwise? By changing some code, building the app, and running it to verify the bad behavior doesn't happen anymore? I don't really see how not writing a unit test (assuming the code is unit-testable in the first place) saves you any time. You are doing testing anyhow. And if it was a critical bug, personally I'd want to feel as confident as possible that I fixed all permutations of it.