[dathinab]

they are not competing

they handle two different cases

anyhow is for type erased errors, which is mainly used for the kind of errors you mainly propagate upward without handling them in any fine grained way. It's mainly used in applications (instead of libraries). For example in a web server anyhow errors will likely yield Internal Serer errors.

thiserror provides a derive (codegen) to easily create your own error. It's much more often used by libraries, but if an application doesn't want to handle this errors they will likely be converted into anyhow errors. A very common use case is to apply it on an enum which represent "one of many errors" e.g. as a dump example `enum Error { BadArgument(...), ConstraintViolation(...), ... }` and it's no absurd in some cases to have a mixture e.g. an enum variant `Unexpected(anyhow::Error)` which represents various very unpexted errors which likely could be bugs and you might have considered panicing there but decided to propagate them instead to avoid panic related problems

[NathanFlurry]

+1 this

I don't understand why this answer is buried deep in a thread & isn't included in the Rust Book, even though it's been conventional wisdom among experienced Rustaceans for a few years now.

[lenkite]

thiserror should be in the stdlib frankly. Or Rust should offer its facilities natively.