unresolved-macro-call on futures_util::join!

[Follpvosten]

With the latest stable and nightly versions, in a new project just depending on tokio and future_util, with this code in main.rs:

#[tokio::main]
async fn main() {
    let bla = async { 1 };
    let blub = async { 2 };
    let (bla, blub) = futures_util::join!(bla, blub);
}

I get this error on the futures_util::join! line:

despite it obviously finding the macro, as the documentation is shown. This did not happen with the stable release before this one.
More info: vscode 1.54.3 (OSS build), Linux 5.10.24, rustup 1.23.1, cargo/rustc 1.50.0

[jonas-schievink]

The macro invokes join_internal!, which is reexported like this:

#[proc_macro_hack(support_nested, only_hack_old_rustc)]
pub use futures_macro::join_internal;

[Follpvosten]

Oh so this really is #6478?

[jonas-schievink]

No, it might be the fact that we don't support attribute macros like #[proc_macro_hack], but if it only appeared recently it might be something else.

[lnicola]

It's #6835 and also #6029.

[jonas-schievink]

#6835 looks like a direct duplicate, so closing in favor of that