error-chain

error-chain is a legacy, unmaintained Rust error-handling crate. A Rust community announcement states plainly that it is "no longer maintained," and the repository has moved to rust-lang-deprecated. Last published version: 0.12.4 (2020).

Migration paths:

• Typed errors -> thiserror or snafu
• Application-level error boxing -> anyhow or eyre

Like failure, the presence of error-chain in a dependency graph is a signal of age. See rust-error-crate-comparison for the modern landscape.