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
   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date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`.