[Arnavion]

I used to maintain a custom derive crate for errors before failure came out, but these days I just use manual impls of `std::error::Error` for libraries and `Box<dyn std::error::Error>` for applications. I can't be bothered to keep up with the Rust error-library-du-jour game, even if it so happens that today's darling custom derive (thiserror) would emit the same `std::error::Error` impl that I write by hand.

Manual impls may be tedious to write, but they change rarely after they've been written, enough that the con of adding one more dependency that may go away tomorrow outweighs the con of writing them manually.

[jfkebwjsbx]

This matches my experience as well. I want to write code that works for years (dependencies make this hard) and is understood by everyone. So explicit is best.