error[E0658]: the precise format of `Fn`-family traits' type parameters is subject to change
  --> $DIR/unboxed-closure-sugar-not-used-on-fn.rs:3:17
   |
LL | fn bar1(x: &dyn Fn<(), Output=()>) {
   |                 ^^^^^^^^^^^^^^^^^ help: use parenthetical notation instead: `Fn() -> ()`
   |
   = note: see issue #29625 <https://github.com/rust-lang/rust/issues/29625> for more information
   = 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
  --> $DIR/unboxed-closure-sugar-not-used-on-fn.rs:7:28
   |
LL | fn bar2<T>(x: &T) where T: Fn<()> {
   |                            ^^^^^^ help: use parenthetical notation instead: `Fn() -> ()`
   |
   = note: see issue #29625 <https://github.com/rust-lang/rust/issues/29625> for more information
   = 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`.