Bug

A bug is a flaw in software that causes an unintended result. Most bugs arise from errors in written code, rather than from a computer itself. Due to the prevalence of engineer-created bugs, some programmers sardonically refer to their bugs as "surprise features".

Albert: Is there a bug in your code? I can't log into my account.
Justin: That's a feature. The site is telling you to go outside and take walk.