not a bug; intentional behavior that seems like a bug
Used in software development to indicate that an observed behavior is by design, not a defect. Often appears in bug tracker comments or documentation.
This behavior is not a bug. It works as specified.
We received a report from a user, but after investigation, we determined it was not a bug.
Compound of 非 (hi, 'non-') and バグ (bagu, 'bug'), a straightforward modern technical term.