regression: trait bound is not satisfied

[INFO] [stdout] error[E0277]: the trait bound `(dyn LoopableJob + 'static): Job` is not satisfied
[INFO] [stdout]    --> src/service.rs:190:18
[INFO] [stdout]     |
[INFO] [stdout] 190 |         self.job.run_once().await
[INFO] [stdout]     |                  ^^^^^^^^ the trait `Job` is not implemented for `(dyn LoopableJob + 'static)`
[INFO] [stdout]     |
[INFO] [stdout] help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
[INFO] [stdout]     |
[INFO] [stdout] 188 | impl Job for LoopingJobService where (dyn LoopableJob + 'static): Job {
[INFO] [stdout]     |                                ++++++++++++++++++++++++++++++++++++++

https://crater-reports.s3.amazonaws.com/beta-1.78-3/beta-2024-03-30/reg/app-frame-0.3.1/log.txt

@estebank

Regression in rust-lang-ci@e890bd9
The PR introducing the regression in this rollup is #120323: On E0277 be clearer about implicit Sized bounds on type p…

searched nightlies: from nightly-2024-01-01 to nightly-2024-03-18
regressed nightly: nightly-2024-02-06
searched commit range: 268dbbb...f067fd6
regressed commit: 4d87c4a

bisected with cargo-bisect-rustc v0.6.8

Host triple: x86_64-unknown-linux-gnu
Reproduce with:

cargo bisect-rustc --start=2024-01-01 --end=2024-03-18

This PR definitely should not have changed behavior :/
cc @estebank

@rustbot

I'll look into what's going on with it anyways -- it at least needs a MCVE

@rustbot claim

Implicitly reordering the Sized predicates as a side-effect of #120323 is the problem here.

pub trait Job: AsJob {
    fn run_once(&self);
}

impl<F: Fn()> Job for F {
    fn run_once(&self) {
        todo!()
    }
}

pub trait AsJob {
}

impl<T: Job + Sized> AsJob for T { // <----- changing this to `Sized + Job` or just `Job` will FIX it.
}

pub struct LoopingJobService {
    job: Box<dyn Job>,
}

impl Job for LoopingJobService {
    fn run_once(&self) {
        self.job.run_once()
    }
}

I assume this is because of an overflow on the AsJob impl that isn't cut off short by the Sized predicate being impossible to satisfy?

@rustbot

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-high

Rollup merge of rust-lang#123302 - compiler-errors:sized-bound-first,…

Unrolled build for rust-lang#123302

#123302 was backported in #123466.

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regression: trait bound is not satisfied #123279

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regression: trait bound is not satisfied #123279

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compiler-errors commented on Mar 31, 2024

compiler-errors commented on Mar 31, 2024

compiler-errors commented on Mar 31, 2024

apiraino commented on Apr 2, 2024

cuviper commented on Apr 12, 2024

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