#[builder(default = ...)] for generic field got error "expected type parameter, found concrete type"

[cshuaimin]

#[derive(TypedBuilder)]
struct Foo<T> {
    #[builder(default = 12)]
    x: T,
}

error[E0308]: mismatched types
  --> tests/tests.rs:60:29
   |
59 |     struct Foo<T> {
   |                - this type parameter
60 |         #[builder(default = 12)]
   |                             ^^ expected type parameter `T`, found integer
   |
   = note: expected type parameter `T`
                        found type `{integer}`