regression: a value of type HashMap<Pulse, u64> cannot be built from

[BoxyUwU]

• https://crater-reports.s3.amazonaws.com/beta-1.85-1/beta-2025-01-12/gh/dimo414.advent-2023/log.txt

[INFO] [stderr]    Compiling advent-2023 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0277]: a value of type `HashMap<Pulse, u64>` cannot be built from an iterator over elements of type `&(Pulse, {integer})`
[INFO] [stdout]    --> src/bin/20/main.rs:278:88
[INFO] [stdout]     |
[INFO] [stdout] 278 |           assert_eq!(config.counts, [(Pulse::Low, low), (Pulse::High, high)].into_iter().collect());
[INFO] [stdout]     |                                                                                          ^^^^^^^ value of type `HashMap<Pulse, u64>` cannot be built from `std::iter::Iterator<Item=&(Pulse, {integer})>`
[INFO] [stdout] 279 |       } }

[compiler-errors]

This one seems to have regressed in:

83965ef #133274

cc @ehuss, tho i'll double check when i'm done bisecting the rest

[theemathas]

Minimized (zipped for your convenience: foo.zip):

src/lib.rs

// This crate is in edition 2021

bar::create_macro! {{
    // This code works on edition 2021, but not edition 2018
    let _ = [1i32].into_iter().collect::<Vec<i32>>();
}}
create_fn!();

bar/src/lib.rs

// This crate is in edition 2018

#[macro_export]
macro_rules! create_macro {
    ($body:tt) => {
        macro_rules! create_fn {
            () => {
                fn a() {
                    $body
                }
            };
        }
    };
}

Cargo.toml

[workspace]
members = ["bar"]

[package]
name = "foo"
version = "0.1.0"
edition = "2021"

[dependencies]
bar = { path = "bar" }

bar/Cargo.toml

[package]
edition = "2018"
name = "bar"
version = "0.1.0"

In stable, the function body is compiled as edition 2021. In beta, it is compiled as edition 2018.

For context: This is the intended usage pattern of the parameterized_test crate.