Rust 1.95.0-beta tries the wrong `LockfileUsage`

[cuviper]

rust-analyzer version: rust-analyzer 1.95.0-beta.1 (ad726b5 2026-03-05)

rustc version: rustc 1.95.0-beta.1 (ad726b506 2026-03-05)

editor or extension: vim-lsp

relevant settings: N/A

repository link (if public, optional): N/A

code snippet to reproduce: cargo new

I see this in Vim :messages:

rust-analyzer: warning: Failed to read Cargo metadata with dependencies for sysroot of `‥/Cargo.toml`: `cargo metadata` exited with an error: error: unexpected argument '--lockfile-path' found

  tip: a similar argument exists: '--locked'

Usage: cargo metadata --format-version <VERSION> --manifest-path <PATH> --filter-platform <TRIPLE> --locked

For more information, try '--help'.

I did a little digging and found that this argument is controlled by:

rust-analyzer/crates/project-model/src/cargo_config_file.rs

Lines 141 to 146 in 2a8f00f

	pub(crate) enum LockfileUsage {
	/// Rust [1.82.0, 1.95.0). `cargo <subcmd> --lockfile-path <lockfile path>`
	WithFlag,
	/// Rust >= 1.95.0. `CARGO_RESOLVER_LOCKFILE_PATH=<lockfile path> cargo <subcmd>`
	WithEnvVar,
	}

So in this case, we should expect it to use the env. However, in the comparison >= MINIMUM_TOOLCHAIN_VERSION_SUPPORTING_LOCKFILE_PATH_ENV (1.95.0-nightly), my prerelease "beta" is lexically less than "nightly". Rust versions are not properly semver-ordered in this regard!

A simple fix would be to just use "beta" in that MINIMUM_...PATH_ENV, then "nightly" is still >= as well.

[ShoyuVanilla]

Yeah, it's my bad 😢 We have fixed(#21716) it in our recent versions but need to backport it to beta.

Edit)

So in this case, we should expect it to use the env. However, in the comparison >= MINIMUM_TOOLCHAIN_VERSION_SUPPORTING_LOCKFILE_PATH_ENV (1.95.0-nightly), my prerelease "beta" is lexically less than "nightly". Rust versions are not properly semver-ordered in this regard!

Oh, I misread your point. beta is lexically less than nightly 😱 Yeah, looks like we need to fix it

[cuviper]

Ah, ok, I was looking at master for the current behavior, but beta's rust-analyzer is even worse since that's comparing to plain 1.95.0, so all prereleases are less than that.

The good news is that this will be moot once 1.95.0 is actually released. :)
(but maybe a fix and backport is still worthwhile for this beta testing period)

[ShoyuVanilla]

The fix is straightforward but I can't do it rn because I'm at work 😢 Gonna fix and test this once I got home but it would be great if someone could do it sooner 😅