What's the word for a software bug that reoccurs after being fixed?
I'm embarking on some test-driven development (TDD) for a project, and I want to use the right term but have forgotten the word.
It's not reversion, but I think it sounds similar.
Though I've used it many times I can't recollect the term right now, and Google isn't helping me.
Addition 1: The bug is imaginary in this case. It only reappears once, after I fixed, because of a new change I introduce. I'm not talking about something that that keeps on popping up.
Addition 2: The correct answer popped up 7 minutes after asking. The amount of bikeshedding the keeps on coming after that is hilarious.