1 error[E0658]: attributes starting with `rustc` are reserved for use by the `rustc` compiler
2 --> $DIR/expand-to-unstable-2.rs:10:10
4 LL | #[derive(Unstable)]
7 = help: add `#![feature(rustc_attrs)]` to the crate attributes to enable
8 = note: this error originates in a derive macro (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`.