error[E0658]: allow_internal_unstable side-steps feature gating and stability checks --> $DIR/feature-gate-allow-internal-unstable.rs:3:1 | LL | #[allow_internal_unstable()] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: add `#![feature(allow_internal_unstable)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0658`.