main.rs

// tokio = { version = "1", features = ["full"] }
// tracing = "0.1.40"
// tracing-subscriber = "0.3.18"
// snafu = "0.8.3"
// exitcode = "1.1.2"

use tracing::{error as log_error};
use snafu::Report;
use tracing_subscriber;

async fn main_result() -> Result<()> { Ok(()) }

#[tokio::main]
async fn main() {
    tracing_subscriber::fmt::init();

    if let Some(error) = main_result().await.err() {
        log_error!("{}", error);
        let report = snafu::Report::from_error(&error);
        eprintln!("{}", report);

        let exit_code =
            match error {
                MyError::Error1 => { exitcode::UNAVAILABLE }
                // ...
            };

        exit(exit_code);
    }
}