regression: parameter type may not live long enough

[Mark-Simulacrum]

[INFO] [stdout] error[E0309]: the parameter type `G` may not live long enough
[INFO] [stdout]    --> src/adapters/intersperse.rs:135:17
[INFO] [stdout]     |
[INFO] [stdout] 125 | impl<'this, L, G> Lender for IntersperseWith<'this, L, G>
[INFO] [stdout]     |      ----- the parameter type `G` must be valid for the lifetime `'this` as defined here...
[INFO] [stdout] ...
[INFO] [stdout] 135 |                 core::mem::transmute::<<Self as Lending<'this>>::Lend, <Self as Lending<'_>>::Lend>((self.separator)())
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `G` will meet its required lifetime bounds
[INFO] [stdout]     |
[INFO] [stdout] help: consider adding an explicit lifetime bound
[INFO] [stdout]     |
[INFO] [stdout] 128 |     G: FnMut() -> <L as Lending<'this>>::Lend + 'this,
[INFO] [stdout]     |                                               +++++++
[INFO] [stdout] 

• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/lender-0.2.1/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/actix-mqtt-client-0.5.0/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/sod-0.3.2/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/gh/zyansheep.advent-of-code-rust/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/milvus-0.2.0/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/mqttp-0.0.0/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/sod-actix-web-0.3.1/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/sod-bus-0.3.1/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/sod-crossbeam-0.3.1/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/sod-log-0.3.1/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/sod-mpsc-0.3.1/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.77-3/beta-2024-02-18/reg/sod-tungstenite-0.3.3/log.txt

[compiler-errors]

I believe this is a mixture of regressions from #120019 (at least the advent-of-code repo is due to this) and #118553 (which I assume the bulk of the remaining crates are due to that).

cc @lcnr @jackh726 for your respective PRs

[apiraino]

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-critical

[lcnr]

going to look at all of them now, believe them to be intended

[lcnr]

lender https://crates.io/crates/lender

affected version 0.2.1, fixed by @aliemjay in WanderLanz/Lender#4 with new version released afaict

actix-mqtt-client https://crates.io/crates/actix-mqtt-client

affected version 0.5.0, fixed by @jackh726 in Syndim/actix-mqtt-client#14, no new release yet

dependencies

• https://crates.io/crates/mqttp

sod https://crates.io/crates/sod

affected version 0.3.2, fixed by @jackh726 in thill/sod#1, not yet merged

dependencies

• https://crates.io/crates/sod-actix-web
• https://crates.io/crates/sod-bus
• https://crates.io/crates/sod-crossbeam
• https://crates.io/crates/sod-log
• https://crates.io/crates/sod-mpsc
• https://crates.io/crates/sod-tungstenite

https://github.com/zyansheep/advent-of-code-rust

depends on lender-0.2.1, fixed by updating the Cargo.toml file.

milvus https://crates.io/crates/milvus

affected version 0.2.0, minimized

Actually unsure which PR fixed this :thinking_face: This previous behavior was unsound? Anyways, opened andreytkachenko/milvus-rs#1

Asked on zulip for help bisecting this: https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/help.20bisecting.20unknown.20soundness.20fix

---

I consider all of these changes to be intended breakage, closing this. cc @rust-lang/types