support wrapping error_chain Error's ? / document that Send+Sync are required on top of std::error::Error #72
Description
Anyhow claims to support wrapping any implementor of std::error::Error, but error_chain's impl seems incompatible:
error[E0277]: `(dyn std::error::Error + std::marker::Send + 'static)` cannot be shared between threads safely
--> src/cli/main.rs:66:25
|
66 | utils::current_dir()?;
| ^ `(dyn std::error::Error + std::marker::Send + 'static)` cannot be shared between threads safely
|
= help: the trait `std::marker::Sync` is not implemented for `(dyn std::error::Error + std::marker::Send + 'static)`
= note: required because of the requirements on the impl of `std::marker::Sync` for `std::ptr::Unique<(dyn std::error::Error + std::marker::Send + 'static)>`
= note: required because it appears within the type `std::boxed::Box<(dyn std::error::Error + std::marker::Send + 'static)>`
= note: required because it appears within the type `std::option::Option<std::boxed::Box<(dyn std::error::Error + std::marker::Send + 'static)>>`
= note: required because it appears within the type `error_chain::State`
= note: required because it appears within the type `rustup::errors::Error`
= note: required because of the requirements on the impl of `std::convert::From<rustup::errors::Error>` for `anyhow::Error`
= note: required by `std::convert::From::from`
rust-lang-deprecated/error-chain#240 is presumably the underlying cause, but perhaps anyhow could do something on it's end via specialisation or using ?Send and ?Sync or something?