Rust 2021 (1.56+) breaks shaku (fixed on 1.59)

[elertan]

Breaking changes introduced by the new version breaks HasComponent impls on the module using the shaku::module macro.
I will try to provide a poc as soon as possible.

https://doc.rust-lang.org/edition-guide/rust-2021/prelude.html
Maybe some documentation as to why this occurs is available.

[elertan]

Can't seem to replicate it using a simple poc..
Here's what I tried on Rust 1.56.1:

use shaku::{module, Component, Interface, HasComponent};

trait User {
    fn id(&self) -> u32;
}

trait Repository<T>: Interface where T: ?Sized {
    fn get_all(&self) -> Vec<Box<T>>;
}

#[derive(Component)]
#[shaku(interface = Repository<dyn User>)]
struct UserRepositoryImpl;

impl Repository<dyn User> for UserRepositoryImpl {
    fn get_all(&self) -> Vec<Box<dyn User>> {
        vec![]
    }
}

module! {
    MyModule {
        components = [UserRepositoryImpl],
        providers = []
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test() {
        let module = MyModule::builder()
            .build();

        let x: &dyn Repository<dyn User> = module.resolve_ref();
        x.get_all();
    }
}

Code above compiles fine.

In my actual codebase I get about 47 errors which all look similar to this:

error[E0277]: the trait bound `_Module: HasComponent<(dyn Repository<(dyn AccountBase + 'static), (dyn Account + 'static), AccountFields> + 'static)>` is not satisfied
  --> _/src/dependency_inversion.rs:9:1
   |
9  | / module! {
10 | |     pub _Module {
11 | |         components = [
12 | |             persistence::database::PoolProviderImpl,
...  |
45 | |     }
46 | | }
   | |_^ the trait `HasComponent<(dyn Repository<(dyn AccountBase + 'static), (dyn Account + 'static), AccountFields> + 'static)>` is not implemented for `_Module`
   |
   = help: the following implementations were found:
             <FuifModule as HasComponent<(dyn AutocompleteService + 'static)>>
             <FuifModule as HasComponent<(dyn ConfigProvider + 'static)>>
             <FuifModule as HasComponent<(dyn DateTimeService + 'static)>>
             <FuifModule as HasComponent<(dyn GoogleAuthService + 'static)>>
           and 24 others
   = note: required because of the requirements on the impl of `shaku::Component<_Module>` for `DefaultProfileService`
   = note: this error originates in the macro `module` (in Nightly builds, run with -Z macro-backtrace for more info)

Note: I removed keywords related to the project with _ as they are not publicly disclosable.
These errors do not occur when I build it with Rust on 1.55.0

Edit:
Realize I kept the name in anyways... 🤦‍♂️. Oh well.

[AzureMarker]

Thanks for opening this issue, I'll take a look soon!

[AzureMarker]

Weird, it shows an error for me in https://github.com/AzureMarker/shaku/blob/master/shaku/tests/repository_service_provider.rs even when still using Rust 2018.
(still investigating)

[elertan]

Weird, it shows an error for me in https://github.com/AzureMarker/shaku/blob/master/shaku/tests/repository_service_provider.rs even when still using Rust 2018.

(still investigating)

Are you using Rust 1.56+ with the 2018 edition or Rust 1.55.0 or lower?
The issue also occurred for me with Rust 1.56+ when using the 2018 edition.
(As in setting the edition to 2018 and compiling on 1.56.1 gives me the same errors)

[AzureMarker]

Yeah, 1.56.1 on 2018

[elertan]

Yeah, 1.56.1 on 2018

Well at least happy to see that it is reproducable. After digging through the release notes of Rust 1.56 nothing really seems like it should affect how this works.
Maybe it is caused by some undocumented change?

[AzureMarker]

Opened bug on rustc: rust-lang/rust#90662

[AzureMarker]

The rustc issue has been closed with a fix, and it should release in 1.59.

[elertan]

Hope to see the Rust 1.59 soon then. Thanks for your involvement to help getting this fixed.
Still surprising to me though that the stable Rust release would introduce breaking changes.
I'll close the issue once 1.59 is released to see if everything works fine by then.

[elertan]

Seems like Rust 1.59 has been released today, I will attempt to build the project I had issues in previously to see if it has been resolved now. For now I had been using nightly to build the project which did not have any issues.

[elertan]

Fixed on 1.59 🎉

[AzureMarker]

Thanks for following up!