@Zoxc : regarding https://github.com/rust-lang/rustc-rayon/pull/4, I've not looked too closely at it yet, but my main concern is that I think our goal is to be removing rustc-rayon, not extending it... in any case, you mentioned that the purpose is to avoid passing in a
&Scope but rather a "longer lived"
&'tcx Scope<'tcx> thing, do you have an in-progress PR for how you plan to use that in rustc specifically?
It will be used to run things which we know will be needed later in the background. https://github.com/rust-lang/rust/pull/67965 runs
early lint checks and HIR map validation in the background that way. I also expect it to be used to load the dep graph in the background, parse files in the background as we see
mod items, write metadata in the background during codegen and for other various queries.