How come you get macro expansion errors? Or is it because you write incorrect syntax in the enum error definitions? The example on the docs page is quite clear

How come you get macro expansion errors? Or is it because you write incorrect syntax in the enum error definitions? The example on the docs page is quite clear: https://docs.rs/thiserror/latest/thiserror/#example https://docs.rs/thiserror/latest/thiserror/#example Including all kinds of errors: Strings, tagged unions and automatically converting from std::io::Error with added context. That one page document is the entire documentation for the thiserror crate.