Regression rust ICE involving const generic expressions and rayon.
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- Dominant language
- Rust
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Description
I got a regression building some of my PhD tooling.
The bug has been reproduced on a rust playground, cf https://github.com/rust-lang/rust/issues/150162#issuecomment-3677848734 (it could perhaps still be minimised further to remove the rayon dependency)
I do note that I use generic_const_exprs, which is known for its instability.
I have identified that the bug doesn't occur on nightly-2025-10-10, I'll bisect the start of the issue.
Code
See https://github.com/rust-lang/rust/issues/150162#issuecomment-3677848734
Meta
rustc --version --verbose:
rustc 1.94.0-nightly (fcf67da03 2025-12-18)
binary: rustc
commit-hash: fcf67da039f42e3905cf6f69e33304299c45149f
commit-date: 2025-12-18
host: x86_64-unknown-linux-gnu
release: 1.94.0-nightly
LLVM version: 21.1.8
Error output
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the Rust Playground reproducer linked in the issue and compare it against nightly-2025-10-10, then review the attached ICE output. Bisect the regression as described; done means the reproducer no longer triggers an internal compiler error and the regression is covered by an appropriate compiler test.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 32/100