问无法使用rocket:: serde ::json::Json，尽管火箭和serde都被列为依赖项

EN

error[E0432]: unresolved import `rocket::serde::json`
 --> src/main.rs:2:20
  |
2 | use rocket::serde::json::Json;
  |                    ^^^^ could not find `json` in `serde`

For more information about this error, try `rustc --explain E0432`.
error: could not compile `my-api` due to previous error

[package]
name = "my-api"
version = "0.1.0"
edition = "2021"
publish = false

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
rocket = "0.5.0-rc.1"
serde = "1.0.130"

#[macro_use] extern crate rocket;
use rocket::serde::{Serialize, json::Json};

#[derive(Serialize)]
struct Location {
    lat: String,
    lng: String,
}

#[get("/?<lat>&<lng>")]
fn location(lat: &str, lng: &str) -> Json<Location> {
    Json(Location {
        lat: 111.1111.to_string(),
        lng: 222.2222.to_string(),
    })
}

#[launch]
fn rocket() -> _ {
    rocket::build().mount("/", routes![location])
}