error[E0658]: is unstable
  --> $DIR/feature-gate-link_cfg.rs:1:1
   |
LL | #[link(name = "foo", cfg(foo))]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #37406 <https://github.com/rust-lang/rust/issues/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`.