error: you should not implement `visit_string` without also implementing `visit_str`
  --> $DIR/serde.rs:39:5
   |
LL | /     fn visit_string<E>(self, _v: String) -> Result<Self::Value, E>
LL | |     where
LL | |         E: serde::de::Error,
LL | |     {
LL | |         unimplemented!()
LL | |     }
   | |_____^
   |
   = note: `-D clippy::serde-api-misuse` implied by `-D warnings`

error: aborting due to previous error