error[E0658]: the target feature `xop` is currently unstable --> $DIR/feature-gate-xop_target_feature.rs:2:18 | LL | #[target_feature(enable = "xop")] | ^^^^^^^^^^^^^^ | = note: see issue #127208 for more information = help: add `#![feature(xop_target_feature)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0658`.