Starter main.rs and lib.rs files for Rust applications

lib.rs

use thiserror::Error;
use tracing as trc;

/// An error that indicates that the program should exit with the given code
#[derive(Error, Debug)]
#[error("Program exited {0}")]
struct Exit(i32);

fn run() {
    // Install tracing for logs
    install_tracing();
    // Install color error printing
    color_eyre::install().expect("Could not install error handler");

    // Start the application and capture errors
    match start() {
        // Do nothing for happy runs!
        Ok(()) => (),
        // Hnadle errors
        Err(report) => {
            // If the error is an exit code
            if let Some(e) = report.downcast_ref::<Exit>() {
                let code = e.0;

                // If the code is zero, exit cleanly
                if code == 0 {
                    std::process::exit(0);

                // If the code is non-zero print the error and then exit with that code
                } else {
                    println!("{:?}", report);
                    std::process::exit(e.0);
                }
            // If the error is any other kind of error print it and exit 1
            } else {
                println!("{:?}", report);
                std::process::exit(1);
            }
        }
    }
}

fn install_tracing() {
    use tracing_error::ErrorLayer;
    use tracing_subscriber::prelude::*;
    use tracing_subscriber::{fmt, EnvFilter};

    // Build the tracing layers
    let fmt_layer = fmt::layer().with_target(false);
    let filter_layer = EnvFilter::try_from_default_env()
        .or_else(|_| EnvFilter::try_new("info"))
        .unwrap();

    // Add all of the layers to the subscriber and initialize it
    tracing_subscriber::registry()
        .with(filter_layer)
        .with(fmt_layer)
        .with(ErrorLayer::default())
        .init();
}

/// Start your program
fn start() -> eyre::Result<()> {
    trc::info!("Starting program");

    Ok(())
}

main.rs

fn main() {
    my_crate::run();
}