Having issues compiling figment with Rocket

[yilmazgunalp]

Hi,

I am newish to Rust and Rocket. I am trying to use Figment with Rocket but it doesn't compile. I am getting this error:

|
= note: see issue #47809 rust-lang/rust#47809 for more information
= help: add #![feature(track_caller)] to the crate attributes to enable

error[E0658]: the #[track_caller] attribute is an experimental feature
--> /home/yg/.cargo/registry/src/github.com-1ecc6299db9ec823/figment-0.9.4/src/figment.rs:176:5
|
176 | #[track_caller]
| ^^^^^^^^^^^^^^^
|
= note: see issue #47809 rust-lang/rust#47809 for more information
= help: add #![feature(track_caller)] to the crate attributes to enable

error[E0658]: use of unstable library feature 'track_caller': uses #[track_caller] which is not yet stable
--> /home/yg/.cargo/registry/src/github.com-1ecc6299db9ec823/figment-0.9.4/src/providers/serialized.rs:80:18
|
80 | loc: Location::caller()
| ^^^^^^^^^^^^^^^^

This is from my Cargo.toml:

serde = { version = "1.0", features = ["derive"] }
figment = { version = "0.9", features = ["toml", "env"] }

This is my main function:

fn main() {
    let port = env::var("PORT").expect("$PORT must be set");

    let figment = Figment::new()
    .merge(Toml::file("Rocket.toml"))
    .merge(Env::prefixed("ROCKET_"));

    rocket::custom(figment)
    .attach(DbConn::fairing())
    .mount("/", routes![
        posts::list,
        posts::new
        ]).launch();
}

I added #[macro_use] extern crate figment; to my main.rs as well but didnt help

[SergioBenitez]

You simply need a newer rustc. rustup update.

[yilmazgunalp]

Thanks! I also had to increase the Figment version to 0.10.3

[SergioBenitez]

That should be unnecessary; there is no compatibility difference between the 0.10.x releases.