Incorrect "operation requires unsafe block" (regression)

[massimiliano-mantione]

rust-analyzer version: (eg. output of "Rust Analyzer: Show RA Version" command)

rust-analyzer version: 0.3.1131-standalone (897a7ec 2022-07-17)

rustc version: (eg. output of rustc -V)

rustc 1.56.1

relevant settings: (eg. client settings, or environment variables like CARGO, RUSTUP_HOME or CARGO_HOME)

Nothing relevant, vscode on Linux, but see below about a rust-toolchain file.

This is a sort of regression of #5996.
I have a workspace where I lock rust version using a rust-toolchain file, to be sure that I use the same one as CI does.

I had the version still locked to 1.56.1, and now I am affected by #5996.
Downgrading rust-analyzer by one single release, or switching to the prerelease, did not fix the issue.

However, upgrading rust to 1.62.1 (e092d0b6b 2022-07-16) (putting 1.62.1 in the rust-toolchain file) fixes the issue.
I will likely keep the upgrade as a workaround (sooner or later I would have upgraded anyway, and I am in the position to also upgrade the CI Dockerfile).

I am reporting this because I think the expectation is that rust-analyzer works with any rustc version, even older ones, and not just the current one.

[lnicola]

I take it you haven't seen the discussion in #12719?

I think the expectation is that rust-analyzer works with any rustc version, even older ones, and not just the current one.

That's a quite a lot to ask for. We don't support pre-1.47 sysroots, and just dropped proc macro support for a bunch of versions in #12798.

[jonas-schievink]

Our Rust support policy is documented in the manual:

Only the latest stable standard library source is officially supported for use with rust-analyzer. If you are using an older toolchain or have an override set, rust-analyzer may fail to understand the Rust source. You will either need to update your toolchain or use an older version of rust-analyzer that is compatible with your toolchain.

Hence, closing.