error[E0658]: use of unstable library feature 'function' --> $DIR/internal-unstable-thread-local.rs:9:32 | LL | thread_local!(static BAR: () = internal_unstable::unstable()); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: add `#![feature(function)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0658`.