proc macro `*` not expanded: proc macro not found

[arturoc]

rust-analyzer version: 6fc5c3c 2022-06-20

rustc version: (latest stable) rustc 1.61.0 (fe5b13d68 2022-05-18)

Since last week, rust analyzer shows several errors for proc macros not found including sometimes cfg_attr in the header of some files where there's no apparent cfg_attr.

Until yesterday's update the errors used to go away after a while but with yesterdays version and with latest pre-release the errors stay.

[flodiebold]

Please report the concrete examples, otherwise it's impossible to tell what's going on. These might be proc macros declared with cfg(not(test)), in which case this is mostly fixed by #12599, or it might be some other reason.

[vvilhonen]

rust-analyzer v0.3.1099

dependencies

tokio = { version = "1.19.2", features = ["full"] }

#[tokio::main]
async fn main() {
    println!("Hello, world!");
}

[{
	"resource": "/src/main.rs",
	"owner": "rustc",
	"code": {
		"value": "unresolved-proc-macro",
		"target": {
			"$mid": 1,
			"external": "https://rust-analyzer.github.io/manual.html#unresolved-proc-macro",
			"path": "/manual.html",
			"scheme": "https",
			"authority": "rust-analyzer.github.io",
			"fragment": "unresolved-proc-macro"
		}
	},
	"severity": 8,
	"message": "proc macro `main` not expanded: proc macro not found",
	"source": "rust-analyzer",
	"startLineNumber": 1,
	"startColumn": 1,
	"endLineNumber": 1,
	"endColumn": 15
}]

[flodiebold]

tokio::main is #12450, which should be fixed in the next release.

[cisaacson]

I have the same issue using ifmt, which has the iwriteln! macro.

The error message is:

proc macro proc_macro_fake_call_site_iwriteln not expanded: proc macro not foundrust-analyzer

It looks like the error prints out for every usage, so 100s of times in my case.

The use statement is:

use ifmt::{iwrite, iwriteln};

After that all other use statements show errors, the repeating message above. cargo check runs with no errors.

An example usage of this macro is:

iwriteln!(code, module_header)?;

As the original report said, this used to show up sometimes and go away. Even after restarting rust-analyzer the spurious error remains.

I must say that rust-analyzer has gotten so much better recently, once you get this fixed it will be awesome.

[flodiebold]

Opened #12614 for ifmt.

[rib]

Hi, I'm currently seeing this with clap:

E.g. with the stub program:

use clap::Parser;

#[derive(Parser)]
#[clap(author, version, about, long_about = None)]
struct Args {
}

fn main() {

}

Cargo.toml:
clap = { version = "3.2.6", features = ["derive"]}

Then I get this error from rust-analyzer:

proc macro clap not expanded: proc macro not found

(Although the code itself builds fine without any errors/warnings via cargo)

rustc 1.61.0 (fe5b13d68 2022-05-18)
rust-analyzer: v0.4.1102 (also saw the same thing with the stable release before trying this pre-release)

[flodiebold]

@rib I can't reproduce this with either the stable or the pre-release. What does the Show RA Version command say?

[arturoc]

I've noticed this doesn't always happens. It just happened to me by pulling latest changes from git while vs code is open. Closing vs code and reopening again fixes it in some cases. I'll try to reproduce it on a minimal example.

[alice-i-cecile]

I can reproduce this with the tokio snippet above, with RA version v0.4.1102.

[flodiebold]

@alice-i-cecile What's the precise error message, and what does Show RA Version say?

[juanmait]

same issue with tokio. Show RA Version says rust-analyzer version: 0.0.0 (427061da1 2022-06-19)

Message says proc macro main not expanded: proc macro not found

The Quick fix suggestions is saying: "Remove unnecessary async"