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Setup Logging with tracing

You’ll need to install tracing and a few related dependencies:

Terminal window
cargo add tracing-error tracing
cargo add tracing-subscriber --features env-filter
cargo add directories lazy_static color-eyre # (optional)

You can paste the following in any module in your project.

use std::path::PathBuf;
use color_eyre::eyre::{Context, Result};
use directories::ProjectDirs;
use lazy_static::lazy_static;
use tracing::error;
use tracing_error::ErrorLayer;
use tracing_subscriber::{self, layer::SubscriberExt, util::SubscriberInitExt, Layer};
lazy_static! {
pub static ref PROJECT_NAME: String = env!("CARGO_CRATE_NAME").to_uppercase().to_string();
pub static ref DATA_FOLDER: Option<PathBuf> =
std::env::var(format!("{}_DATA", PROJECT_NAME.clone())).ok().map(PathBuf::from);
pub static ref LOG_ENV: String = format!("{}_LOGLEVEL", PROJECT_NAME.clone());
pub static ref LOG_FILE: String = format!("{}.log", env!("CARGO_PKG_NAME"));
fn project_directory() -> Option<ProjectDirs> {
ProjectDirs::from("com", "kdheepak", env!("CARGO_PKG_NAME"))
pub fn get_data_dir() -> PathBuf {
let directory = if let Some(s) = DATA_FOLDER.clone() {
} else if let Some(proj_dirs) = project_directory() {
} else {
pub fn initialize_logging() -> Result<()> {
let directory = get_data_dir();
let log_path = directory.join(LOG_FILE.clone());
let log_file = std::fs::File::create(log_path)?;
.or_else(|_| std::env::var(LOG_ENV.clone()))
.unwrap_or_else(|_| format!("{}=info", env!("CARGO_CRATE_NAME"))),
let file_subscriber = tracing_subscriber::fmt::layer()
/// Similar to the `std::dbg!` macro, but generates `tracing` events rather
/// than printing to stdout.
/// By default, the verbosity level for the generated events is `DEBUG`, but
/// this can be customized.
macro_rules! trace_dbg {
(target: $target:expr, level: $level:expr, $ex:expr) => {{
match $ex {
value => {
tracing::event!(target: $target, $level, ?value, stringify!($ex));
(level: $level:expr, $ex:expr) => {
trace_dbg!(target: module_path!(), level: $level, $ex)
(target: $target:expr, $ex:expr) => {
trace_dbg!(target: $target, level: tracing::Level::DEBUG, $ex)
($ex:expr) => {
trace_dbg!(level: tracing::Level::DEBUG, $ex)

Call initialize_logging()? in your main() function.

The log level is decided by the ${YOUR_CRATE_NAME}_LOGLEVEL environment variable (default = log::LevelFilter::Info).

Additionally, the location of the log files would be decided by your environment variables. See the section on XDG directories for more information.

Top half is a terminal with the TUI showing a Vertical split with tui-logger widget. Bottom half is a terminal showing the output of running tail -f on the log file.