Outdated toolchain version error is hard to understand

[moritzmucha]

rust-analyzer version: 0.3.2711

rustc version: rustc 1.85.0 (4d91de4e4 2025-02-17)

editor or extension: VSCode

relevant settings: none

The message rust-analyzer produces when encountering an outdated toolchain version:

path/to/Cargo.toml is using an outdated toolchain version 1.85.0 but rust-analyzer only supports 1.90.0 and higher. Consider using the rust-analyzer rustup component for your toolchain or upgrade your toolchain to a supported version.

... can be very confusing, especially if it suddenly starts appearing after VSCode has silently updated to a new rust-analyzer version that drops support for older toolchain versions (like 0.3.2711)

1. It makes the user think their Cargo.toml is the issue
2. It's a bit unclear in how to resolve the issue (for someone unfamiliar with rustup)

Better wording might be:

This project (path/to/Cargo.toml) uses the Rust toolchain version 1.85.0, but rust-analyzer requires 1.90.0 or higher. You can update your toolchain by running rustup update, or manually change overrides (if present).

[ChayimFriedman2]

AFAIK the comment about rustup wasn't to update rust-analyzer (this certainly doesn't apply to the VSCode extension), but rather to point the extension to use the rustup server, since it is guaranteed to always work with the toolchain.