The most simplest of doing error handling in rust is by returning String as a Box<Error>.

As you can see by running the example, this only prints out the last Error.

If the rust main function returns an Err(), this Err() will be displayed with std::fmt::Debug.

use std::error::Error;
use std::result::Result;

fn do_some_io() -> Result<(), Box<Error>> {
    Err("do_some_io error")?;
    Ok(())
}

fn func2() -> Result<(), Box<Error>> {
    if let Err(_) = do_some_io() {
        Err("func2 error")?;
    }
    Ok(())
}

fn func1() -> Result<(), Box<Error>> {
    if let Err(_) = func2() {
        Err("func1 error")?;
    }
    Ok(())
}

fn main() -> Result<(), Box<Error>> {
    func1()
}