vlib/v/checker/tests/struct_field_reference_type_err.vv:12:16: error: reference field `Animal.duck.age` must be initialized (part of struct `Duck`)
   10 | 
   11 | fn main() {
   12 |     mut animal := Animal{
      |                   ~~~~~~~
   13 |         ageee: 20
   14 |     }
vlib/v/checker/tests/struct_field_reference_type_err.vv:12:16: error: reference field `Duck.age` must be initialized
   10 | 
   11 | fn main() {
   12 |     mut animal := Animal{
      |                   ~~~~~~~
   13 |         ageee: 20
   14 |     }
vlib/v/checker/tests/struct_field_reference_type_err.vv:17:3: error: reference field must be initialized with reference
   15 | 
   16 |     animal.duck = Duck{
   17 |         age: animal.ageee
      |         ~~~~~~~~~~~~~~~~~
   18 |     }
   19 |     dump(animal.duck.age)
