warning: unknown diagnostic attribute
  --> $DIR/non_existing_attributes_accepted.rs:2:15
   |
LL | #[diagnostic::non_existing_attribute]
   |               ^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default

warning: unknown diagnostic attribute
  --> $DIR/non_existing_attributes_accepted.rs:7:15
   |
LL | #[diagnostic::non_existing_attribute(with_option = "foo")]
   |               ^^^^^^^^^^^^^^^^^^^^^^

warning: 2 warnings emitted