error[E0658]: the `#[expect]` attribute is an experimental feature --> $DIR/expect_missing_feature_gate.rs:5:1 | LL | #[expect(unused)] | ^^^^^^^^^^^^^^^^^ | = note: see issue #54503 for more information = help: add `#![feature(lint_reasons)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0658`.