error[E0658]: the precise format of `Fn`-family traits' type parameters is subject to change. Use parenthetical notation (Fn(Foo, Bar) -> Baz) instead
  --> $DIR/unboxed-closure-sugar-not-used-on-fn.rs:3:13
   |
LL | fn bar1(x: &Fn<(), Output=()>) {
   |             ^^^^^^^^^^^^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/29625
   = help: add #![feature(unboxed_closures)] to the crate attributes to enable

error[E0658]: the precise format of `Fn`-family traits' type parameters is subject to change. Use parenthetical notation (Fn(Foo, Bar) -> Baz) instead
  --> $DIR/unboxed-closure-sugar-not-used-on-fn.rs:7:28
   |
LL | fn bar2<T>(x: &T) where T: Fn<()> {
   |                            ^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/29625
   = help: add #![feature(unboxed_closures)] to the crate attributes to enable

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0658`.