error[E0308]: mismatched types
  --> $DIR/return-from-diverging.rs:4:12
   |
LL | fn fail() -> ! {
   |              - expected `!` because of return type
LL |     return "wow";
   |            ^^^^^ expected `!`, found `&str`
   |
   = note:   expected type `!`
           found reference `&'static str`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0308`.