Follow these steps:

1. Open the Cargo.toml file that has been generated earlier for you.

2. Under [dependencies], add the following line:

log = "0.4.1"
env_logger = "0.5.3"

3. If you want, you can go to log's (https://crates.io/crates/log) or env_logger's (https://crates.io/crates/env_log) crates.io pages to check for the newest version and use that one instead.
4. In the folder bin, create a file called logging.rs.

5. Add the following code and run it with RUST_LOG=logging cargo run --bin logging if you're on a Unix-based system. Otherwise, run $env:RUST_LOG="logging"; cargo run --bin logging on Windows:

1   extern crate env_logger;
2   #[macro_use]
3   extern crate log;
4   use log::Level;
5 
6   fn main() {
7     // env_logger's priority levels are:
8     // error > warn > info > debug > trace
9     env_logger::init();
10    // All logging calls log! in the background
11    log!(Level::Debug, "env_logger has been initialized");
12 
13    // There are convenience macros for every logging level 
       however
14    info!("The program has started!");
15 
16    // A log's target is its parent module per default 
17    // ('logging' in our case, as we're in a binary)
18    // We can override this target however:
19    info!(target: "extra_info", "This is additional info that 
       will only show if you 
20    activate info level logging for the extra_info target");
21 
22    warn!("Something that requires your attention happened");
23 
24    // Only execute code if logging level is active
25    if log_enabled!(Level::Debug) {
26    let data = expensive_operation();
27    debug!("The expensive operation returned: "{}"", data);
28    }
29 
30    error!("Something terrible happened!");
31  }
32 
33  fn expensive_operation() -> String {
34    trace!("Starting an expensive operation");
35    let data = "Imagine this is a very very expensive 
       task".to_string();
36    trace!("Finished the expensive operation");
37    data
38  }