error[E0308]: mismatched types
   ╭▸ $DIR/flag-human.rs:9:17
   │
LL │ …t _: () = 42;
   │       ┬─   ━━ expected `()`, found integer
   │       │
   ╰╴      expected due to this

error: aborting due to 1 previous error

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