Display a the chain of an error. Most useful as Result<(), E> for your fn main(),
and in conjunction with thiserror.
This crate simply plagiarized extracted all the relevant formatting code from
anyhow.
```rust use std::error::Error; use std::fmt::{self, Write};
pub enum MyError { Variant1(Error1), Variant2(Error2), }
impl fmt::Debug for MyError { fn fmt(&self, f: &mut fmt::Formatter<'>) -> fmt::Result { prettyerrordebug::prettyerror_debug(self, f) } }
impl fmt::Display for MyError { fn fmt(&self, f: &mut fmt::Formatter<'>) -> fmt::Result { match self { MyError::Variant1() => write!(f, "Error variant 1 happened"), MyError::Variant2(_) => write!(f, "Error variant 2 happened"), } } }
impl Error for MyError { fn source(&self) -> Option<&(dyn Error + 'static)> { match self { MyError::Variant1(source) => Some(source), MyError::Variant2(source) => Some(source), } } }
fn main() -> Result<(), MyError> { … } ```