Tracing in an application

---

examples/tracing/demo-application/Cargo.toml

[package]
name = "demo-application"
version = "0.1.0"
edition = "2024"

[dependencies]
demo-lib = { version = "0.1.0", path = "../demo-lib" }
tracing = "0.1"
tracing-subscriber = "0.3.0"

examples/tracing/demo-application/src/main.rs

use demo_lib::add;
use tracing::{Level, info};
use tracing_subscriber::FmtSubscriber;

fn main() {
    // Set up a tracing subscriber that logs to stdout.
    let subscriber = FmtSubscriber::builder()
        .with_max_level(Level::TRACE)
        .finish();
    tracing::subscriber::set_global_default(subscriber).expect("setting default subscriber failed");

    info!("Before");

    add(2, 3);

    info!("after");
}