error[E0658]: link cfg is unstable --> $DIR/feature-gate-link_cfg.rs:1:22 | LL | #[link(name = "foo", cfg(foo))] | ^^^^^^^^ | = note: see issue #37406 for more information = help: add `#![feature(link_cfg)]` to the crate attributes to enable error: aborting due to previous error For more information about this error, try `rustc --explain E0658`.