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 = note: see issue #29642 <https://github.com/rust-lang/rust/issues/29642> for more information
8 = help: add `#![feature(rustc_attrs)]` to the crate attributes to enable
9 = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
11 error: aborting due to previous error
13 For more information about this error, try `rustc --explain E0658`.