1 error[E0658]: the `#[rustc_error]` attribute is just used for rustc unit tests and will never be stable
2 --> $DIR/feature-gate-generic_associated_types_extended.rs:3:1
7 = help: add `#![feature(rustc_attrs)]` to the crate attributes to enable
9 error: aborting due to previous error
11 For more information about this error, try `rustc --explain E0658`.