#[diagnostic::non_existing_attribute] //~^ERROR `#[diagnostic]` attribute name space is experimental [E0658] //~|WARNING unknown diagnostic attribute [unknown_diagnostic_attributes] pub trait Bar { } #[diagnostic::non_existing_attribute(with_option = "foo")] //~^ERROR `#[diagnostic]` attribute name space is experimental [E0658] //~|WARNING unknown diagnostic attribute [unknown_diagnostic_attributes] struct Foo; fn main() { }