Warning
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Hello,
I happen to browse the source code of the standard library in Rust while working on my projects. It helps to understand how to use it more efficient. However, if I jump to some structure or function from the standard library, I see some errors in the log file of Rust Analyzer. It seems keeping well, though. I think so because all the intellisense functions work fine. By the "intellisense functions" I mean: completion, go to definition, find references, rename symbol etc. The PID of the process remains the same, so I the process doesn't crash.
2025-07-27T21:05:03.257493Z ERROR FetchWorkspaceError: rust-analyzer failed to load workspace: Failed to load the project at /home/oldhome/laladrik/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc/Cargo.toml: Failed to read Cargo metadata from Cargo.toml file /home/oldhome/laladrik/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc/Cargo.toml, Some(Version { major: 1, minor: 82, patch: 0 }): Failed to run `cd "/home/oldhome/laladrik/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc" && RUSTUP_TOOLCHAIN="/home/oldhome/laladrik/.rustup/toolchains/stable-x86_64-unknown-linux-gnu" "/home/laladrik/.cargo/bin/cargo" "metadata" "--format-version" "1" "--manifest-path" "/home/oldhome/laladrik/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc/Cargo.toml" "--filter-platform" "x86_64-unknown-linux-gnu"`: `cargo metadata` exited with an error: error: failed to load manifest for workspace member `/home/oldhome/laladrik/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std`
referenced by workspace at `/home/oldhome/laladrik/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/Cargo.toml`
Caused by:
failed to parse manifest at `/home/oldhome/laladrik/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/Cargo.toml`
Caused by:
the cargo feature `public-dependency` requires a nightly version of Cargo, but this is the `stable` channel
See https://doc.rust-lang.org/book/appendix-07-nightly-rust.html for more information about Rust release channels.
See https://doc.rust-lang.org/cargo/reference/unstable.html#public-dependency for more information about using this feature.
Let me emphasize that Rust Analyzer does seem working. However, I have a feeling that some misconfiguration causes the error. This error does not affect my work now, but I had it before. At that moment Rust Analyzer failed to work in the dependencies of my projects. I couldn't fix that on that computer and I just worked without intellisense. I'm just afraid that it might happen again.
The text of the error
the cargo feature `public-dependency` requires a nightly version of Cargo
I struggle to understand the text for a couple of reasons:
public-dependency. It's triggered by the line from the rustc. This line appeared 2 years ago, but I started getting the error about two weeks ago. I didn't change my dev Rust environment either.master branch. Therefore, Rust analyzer would fail even with the updated version of Rust toolchain.Observations
cargo metadata. From the log it can be seen that Rust Analyzer calls it. Given that, I assume that the error is expected from Cargo for projects with the feature. Therefore, I guess that Rust Analyzer is not supposed to run cargo metadata for the folder with the source code of the standard library.rustup and Cargo are different. Could it affect the work of Rust Analyzer?Configuration
I don't configure anything regarding the Rust toolchain in Rust Analyzer. The configuration of Rust Analyzer is here, though:
{
"checkOnSave": true,
"check":{
"extraArgs":["--no-deps"],
"command":"clippy"
}
}
The environment I work in
One more thing on the versions:
The latest version of Rust Analyzer doesn't emit the error. However, it says that it can't obtain the package "compiler_builtins", because it needs "edition 2024". I guess it means that I have to switch my cargo project to "edition 2024". Transition to the change would require some extra work, which can't be taken for the moment.
I appreciate anyone who knows what's the error about or even knows how to fix it
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