ICE when building regex-syntax with -Zvalidate-mir

[saethlin]

Code

Build regex-syntax-0.7.5 (or any crate that uses regex, which is a lot) with -Zvalidate-mir.

Meta

rustc --version --verbose:

rustc 1.75.0-dev
binary: rustc
commit-hash: unknown
commit-date: unknown
host: x86_64-unknown-linux-gnu
release: 1.75.0-dev
LLVM version: 17.0.2

🤔 that seems wrong. This is a compiler built from eb0f3ed.

I think this ICE might not have hit nightly yet.

Error output

error: internal compiler error: compiler/rustc_const_eval/src/util/compare_types.rs:68:13: Map<core::slice::Iter<'static, (&'static str, &'static [(char, char)])>, {closure@src/unicode.rs:684:49: 684:64}>, Map<core::slice::Iter<'_, (&str, &[(char, char)])>, {closure@src/unicode.rs:684:49: 684:64}>

Backtrace doesn't fit in a GitHub issue.

rustc-ice-2023-10-03T13:28:20.766588558Z-162599.txt

[Luk-ESC]

Minimized to:

fn ages() -> Option<impl Iterator> {
    None::<std::slice::Iter<()>>
}

fn main(){}