Proc-macro derivative::Derivative unresolved

[edwin0cheng]

Not working for me unfortunately.

Settings are on true

➜ rustc --version
rustc 1.51.0-nightly (da305a2b0 2021-01-05)

Originally posted by @aaomidi in #6053 (comment)

[edwin0cheng]

[Copy from original issue]

@aaomidi Confirm your bug in rustc-stable,

maybe related to cfg_attr(not(test)...) ?

https://github.com/mcarton/rust-derivative/blob/770c67484a872470ca782202e13fc70a35e2695b/src/lib.rs#L76-L80

#[cfg_attr(not(test), proc_macro_derive(Derivative, attributes(derivative)))]
pub fn derivative(input: TokenStream) -> TokenStream {
    let mut errors = proc_macro2::TokenStream::new();

    let mut output = match syn::parse::<syn::DeriveInput>(input) {
        Ok(parsed) => {
            ast::Input::from_ast(&parsed, &mut errors)
                .map(|mut input| derive_impls(&mut input, &mut errors))
                .unwrap_or_default()
        },
        Err(error) => {
            errors.extend(error.to_compile_error());
            Default::default()
        }
    };

    output.extend(errors);
    output.into()
}

[jonas-schievink]

maybe related to cfg_attr(not(test)...) ?

Yeah that's it. We always set cfg(test).

[flodiebold]

So, this is kind of related to #6117, #2414 and #7225.

[aaomidi]

Confirmed the bug is in stable too. Although I'm not 100% sure how to make sure rust-analyzer is running with the stable toolchain. I just used rustup to change the default and hoped for the best.

[Rua]

I'm running into this as well with Derivative, using rustc 1.52.0-beta.3, rust-analyzer version: 2021-04-12-92-g7570212a5.

[edwin0cheng]

It will be fixed by the last item of #8486 :

• correctly handle "duplicated" crates in the crate graph. I.e, when cfg(test) crate depends on itself without cfg(test).

[sbrocket]

8b77e26 appears to have fixed this with some manual intervention; you can now add derivative to rust-analyzer.cargo.unsetTest (and then reload the window or restart the RA server).

[cheako]

I used use derivative::*; and it's better.

[sunilkr]

I still have this issue with use derivative::Derivative;. use derivative::*; just removes the unresolved error, but docs on hover or any such feature of VSCode doesn't work. It compiles just fine though. Is there a plan to fix this? I am using default RA settings.

RA: 
Released on    2/10/2020, 14:54:28
Last updated   2/9/2022, 06:16:38
Identifier     matklad.rust-analyzer

$ rustc -V
rustc 1.56.1 (59eed8a2a 2021-11-01)

[flodiebold]

@sunilkr Right now, you will need to use the rust-analyzer.cargo.unsetTest setting.

[zeenix]

It's been more than 1.4 years of this issue, any update on it getting resolved soon?

[lnicola]

There is a workaround in the comment above.

[zeenix]

There is a workaround in the comment above.

Thanks but the workaround needs to be applied by each dev on their own. I got people looking at my crate's source (possibly contributing) and getting annoyed by my use of derivative.

[bjorn3]

You can set it in the .vscode/settings.json file in your repository. Then it will apply to everyone opening your project.

[zeenix]

You can set it in the .vscode/settings.json file in your repository. Then it will apply to everyone opening your project.

Thanks, that's much better indeed. Still that means every project having to do this.

[cyqsimon]

Is this issue fixed now? I had a project that used the use derivative::*; workaround, but today when I checked, use derivative::Derivative; no longer seems to error on my Linux box (rust v1.61.0). Can someone please help confirm/refute this finding?

[zeenix]

@cyqsimon Yeah, I am unable to reproduce either.

[flodiebold]

This is fixed now, unless you're using derivative as a path dependency.