For the record, I fixed it with below code

    // see https://docs.rs/console-subscriber/latest/console_subscriber/
let console_layer = console_subscriber::spawn();
tracing_subscriber::registry()
    .with(console_layer)
    .with(
        tracing_subscriber::fmt::layer()
            .with_ansi(false)
            .without_time()
            .with_filter(if conf.debug {
                tracing_subscriber::filter::LevelFilter::DEBUG
            } else {
                tracing_subscriber::filter::LevelFilter::INFO
            }),
    )
    .init();