1 error[E0658]: use of unstable library feature 'core_intrinsics': intrinsics are unlikely to ever be stabilized, instead they should be used through stabilized interfaces in the rest of the standard library
2 --> $DIR/expand-to-unstable.rs:8:10
4 LL | #[derive(Unstable)]
7 = help: add `#![feature(core_intrinsics)]` to the crate attributes to enable
8 = note: this error originates in the derive macro `Unstable` (in Nightly builds, run with -Z macro-backtrace for more info)
10 error: aborting due to previous error
12 For more information about this error, try `rustc --explain E0658`.