The general advice is good (except for the awkward use of std error), so for anyone who wants to know what rustaceans are actually using:

- std error when it’s required

- anyhow for flexibly dealing with large classes of errors and rethrowing (often in bin crates or internally in a lib crate ), use anyhow::Context to tag errors

- thiserror for building and generating custom errors (in a lib crate)

- miette/eyre for more advanced features

Watch out for exposing error types in public API because then you are bound to push a breaking change if the upstream does.

Anyhow will probably never have a v2 at this point IMO, the entire Rust ecosystem might have to rev!

[EDIT] dont want to suggest that people avoid stackerror, just want to show what other ecosystem projects there are! stackerror seems to fit the hole of anyhow.

Three. Three distinct consumers. Get that in your head. When your application errors out on startup, it's the user who sees the error message. File system errors without seeing the path of the file are useless.