Configuration for additional_derives_ignore

[jeff1010322]

wit-bindgen has a feature to disable certain variants and records from being included for the additional_derives:
bytecodealliance/wit-bindgen#1199

Looks like this is just empty currently:

cargo-component/src/bindings.rs

Line 112 in 40a4155

additional_derive_ignore: Vec::new(),

I would like to be able to set the derives for serde, but the generated code has errors due to it adding these derives to imported types from wasi io:

[package.metadata.component.bindings]
derives = ["serde::Serialize", "serde::Deserialize"]

 LastOperationFailed(Error),
                 ^^^^^ the trait `Deserialize<'_>` is not implemented for `bindings::wasi::io::error::Error`

Can this be implemented so that we can specify this value in the Cargo metadata?

[pchickey]

My recommendation for the moment is that you should just use wit-bindgen directly instead of through cargo component. A lot of what cargo component does is just wrap that crate, and we aren’t finding that to be the best choice for users as the ecosystem evolves.

[jeff1010322]

Thanks for the suggestion! Just to confirm I was able to get the derives working by using the wit-bindgen macro directly. However, I think it would still be nice to have this feature in Cargo Component eventually. Its nice to be able to see and check in the generated bindings for guest components.