No error shown when running cargo metadata on the sysroot fails

[AlanHale25]

rust-analyzer version:
0.4.2329

rustc version: 1.85.0

editor or extension: VSCode

relevant settings: Fresh VSCode and Rust-Analyzer installation

code snippet to reproduce:

// add your code here

[lnicola]

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

You're supposed to fill these in, but you probably have an old toolchain. Only 1.82 and newer are supported at the moment.

[AlanHale25]

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

You're supposed to fill these in, but you probably have an old toolchain. Only 1.82 and newer are supported at the moment.

Hi Sorry, I just filled it in now. I have version 1.85.0

[lnicola]

Do you have rust-src installed or any errors in the status bar? Does it happen in a new project?

[AlanHale25]

I have rust-src installed: PS C:\Users\Alan\Rust-Project> rustup component list
cargo-x86_64-pc-windows-msvc (installed)
clippy-x86_64-pc-windows-msvc (installed)
llvm-bitcode-linker-x86_64-pc-windows-msvc
llvm-tools-x86_64-pc-windows-msvc
rls-x86_64-pc-windows-msvc
rust-analysis-x86_64-pc-windows-msvc
rust-analyzer-x86_64-pc-windows-msvc (installed)
rust-docs-x86_64-pc-windows-msvc (installed)
rust-src (installed)

There are no errors on the status bar.
New projects also have the issue.
Code completions also seems to not be working.

[lnicola]

What do you get for "rust-analyzer: Status"?

[AlanHale25]

When I run it rust-analyzer: Status via the command palette I get this huge json file:

Workspaces:
Loaded 140 packages across 1 workspace.
Workspace root folders: [AbsPath("C:\\Users\\axh444\\rust_project\\Cargo.toml")]
Analysis:
24mb of files
2356 trees, 128 preserved
29859 trees, 512 preserved (macros)
0b of library index symbols (0)
1766b of module index symbols (14)
645mb in total

Debug info:
101252 attribute query entries, 351986 total attributes (8mb for storing entries)
32028 ast id maps
324 block def maps
Version: 
1.85.0 (4d91de4e 2025-02-17)
[snip]

[lnicola]

Sounds like it's working fine. Does it show Unknown even for something like let s = String::new();? Can you Go to definition on String?

[AlanHale25]

Yes, it shows unknown for strings. Vec for vec of strings. It even shows unknown for hardcoded type. e.g
It shows unknown for my string if defined as below

let my_string: String = format!("Hello {}", "world");
my_string

I'm unable to go to string definition either.

[lnicola]

Maybe your toolchain got corrupted? Try rustup toolchain remove 1.85 stable, rustup toolchain install stable --components rust-src.

[AlanHale25]

Uninstalling and reinstalling rust-analyzer and rustup via https://www.rust-lang.org/tools/install did not work, as in it still shows types as unknown.

I had faced this issue before on a previous new install. I did see an issue on here which advised on downloading a pack, that solved my problem at the time, but I can't find the issue it was written on now.

[ByteXiang]

#18560 (comment) . I've mentioned the same problem before, but using 1.81.0 all the time is fine. After updating the ruat-analyzer extension in VSCODE today, 1.18.0 also mentions { unknow } , which I found only for prelude pre-imported modules. I'm not sure if it has anything to do with the image source cargo has set up, but the company's internal network only synced crates up to 2024-08-01.

[AlanHale25]

Finally managed to get it to work.
The issue was the std dependencies where not being built as I'm behind a corporate firewall.

The Solution was to include at $CARGO_HOME/config.toml; the config.toml should include your source and registry configuration (However you usually get through to the internet through the firewall.)

I got to the solution by attempting to run cargo metadata "~/.rustup/toolchains/stable-x86_64-pc-windows-msvc/lib/rustlib/src/rust/library" , Which failed with spurious network connection as the error message. That gave me the hint.

Thank you @ByteXiang your suggestion pointed me to the right direction. #17759

Thank you @lnicola for your effort and help.

[lnicola]

So we don't show an error on cargo metadata? That sounds like a bug.

[AlanHale25]

Yup, the error only appears after going to -> cd $(rustc --print sysroot)/lib/rustlib/src/rust/library && __CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS=nightly

And then running -> cargo metadata