error[E0599]: no method named `with_field2` found for struct `Reg` in the current scope
  --> $DIR/omit_setter.rs:15:10
   |
3  | bitstruct! {
   | ---------- method `with_field2` not found for this
...
15 |         .with_field2(2); // fails because omit_setter was specified on field2
   |          ^^^^^^^^^^^ help: there is an associated function with a similar name: `with_field1`