Suspiciously long compile time when using traits

[PolyMeilex]

I have code like this:

use ashpd::desktop::file_chooser::SaveFileRequest;
use std::future::Future;

struct SomeStruct;

pub trait SomeTrait {
    fn some_method(self) -> Box<dyn Future<Output = ()>>;
}

impl SomeTrait for SomeStruct {
    fn some_method(self) -> Box<dyn Future<Output = ()>> {
        Box::new(async move {
            SaveFileRequest::default().send().await.ok();
        })
    }
}

For no apparent reason, it takes 96s to compile in release mode.
This is the case only when trait is used, and .await is actually called.

This bug report would most likely be better fitted in rustc, but perhaps you have some ideas, so I'm reporting here.

rustc 1.72.0
cargo_timings.zip

related: PolyMeilex/rfd#126

[bilelmoussaoui]

Heh. I have no idea at all what is causing this, the library is also used in various GTK apps and haven't heard of any complaints about this very long compile time until now. I don't think we do anything suspicious in ashpd that would make compile time this slow. I would say a rustc bug report would be more actionable

[bilelmoussaoui]

If you end up opening a bug against rustc, please share the link here so i can ask people around and see if someone familiar with rustc could have a look at it

[bilelmoussaoui]

Apparently, this is rust-lang/rust#115297. Do you mind testing with 1.71?

[PolyMeilex]

Yep, it seems plausible, it works in 1.71

[bilelmoussaoui]

Let us close this one then.