Macro bug

macro_rules! bug {
    () => { ... };
    ($msg:expr) => { ... };
    ($msg:expr,) => { ... };
    ($fmt:expr, $($arg:tt)+) => { ... };
}

A macro for triggering an ICE. Calling bug instead of panicking will result in a nicer error message and should therefore be preferred over panic/unreachable or others.

If you have a span available, you should use span_bug instead.

If the bug should only be emitted when compilation didn’t fail, DiagCtxtHandle::span_delayed_bug may be useful.