error[E0658]: `#[prelude_import]` is for use by rustc only --> $DIR/feature-gate-prelude_import.rs:1:1 | LL | #[prelude_import] | ^^^^^^^^^^^^^^^^^ | = help: add `#![feature(prelude_import)]` to the crate attributes to enable error: aborting due to previous error For more information about this error, try `rustc --explain E0658`.