error[E0308]: mismatched types
  --> tests/compile-fail/span-input-setter.rs:26:21
   |
26 |     input.set_field(22);
   |           --------- ^^ expected `&mut dyn Db`, found integer
   |           |
   |           arguments to this method are incorrect
   |
   = note: expected mutable reference `&mut (dyn Db + 'static)`
                           found type `{integer}`
note: method defined here
  --> tests/compile-fail/span-input-setter.rs:18:5
   |
16 | #[salsa::input]
   | ---------------
17 | pub struct MyInput {
18 |     field: u32,
   |     ^^^^^