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 (the "Play" button in upper right of the code block), 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()
}