...The goal is to enable library authors to build expressive, typed error types, with readable Display implementations (via #[error("...")] annotations) as well as From conversions (#[from]), source tracking (#[source]), and optionally backtraces. It is designed so that switching from handwritten error implementation to using this error is not a breaking change: you retain the same API. The README shows examples: an enum with variants annotated by #[error("…")] and #[from] fields to derive the appropriate trait impls. The crate expects rustc ≥ 1.68+. The README also outlines how you choose; use thiserror if you care about designing your own error-types (e.g., for libraries) vs anyhow for applications.