Bug: `rustlings lsp` not working with latest `rust-analyzer` VS Code Extension version.

[jojobii-arks]

Issue

On the latest version of the rust-analyzer extension (v0.3.1463), the rust-project.json that is generated from running rustlings lsp is seemingly ignored. IntelliSense, autocomplete, etc., cannot be used despite the rust-project.json being generated and rust-analyzer extension being enabled.

Temporary Solution

Roll back rust-analyzer extension version to v0.3.1451.

How to Replicate

• Clone rustlings repository and install rustlings
• Download and enable rust-analyzer v0.3.1463 from Extension Marketplace
• Run rustlings lsp and restart VSCode.
• Attempt to edit exercise .rs files and observe IntelliSense not working.

System Details

rust-analyzer VS Code Extension version: v0.3.1463

rustc --version

rustc 1.68.2 (9eb3afe9e 2023-03-27)

rustlings --version

v5.4.1

ls -la

total 20365
drwxr-xr-x 1 josep 197609       0 Apr  4 07:58 ./
drwxr-xr-x 1 josep 197609       0 Apr  2 10:29 ../
-rw-r--r-- 1 josep 197609   53199 Apr  2 10:29 .all-contributorsrc
drwxr-xr-x 1 josep 197609       0 Apr  2 10:29 .devcontainer/
-rw-r--r-- 1 josep 197609     109 Apr  2 10:29 .editorconfig
drwxr-xr-x 1 josep 197609       0 Apr  3 05:56 .git/
drwxr-xr-x 1 josep 197609       0 Apr  2 10:29 .github/
-rw-r--r-- 1 josep 197609     179 Apr  2 10:29 .gitignore
-rw-r--r-- 1 josep 197609     169 Apr  2 10:29 .gitpod.yml
drwxr-xr-x 1 josep 197609       0 Apr  2 10:29 .vscode/
-rw-r--r-- 1 josep 197609   69063 Apr  2 10:29 AUTHORS.md
-rw-r--r-- 1 josep 197609   17152 Apr  2 10:29 Cargo.lock
-rw-r--r-- 1 josep 197609     533 Apr  2 10:29 Cargo.toml
-rw-r--r-- 1 josep 197609   45620 Apr  2 10:29 CHANGELOG.md
-rw-r--r-- 1 josep 197609    4301 Apr  2 10:29 CONTRIBUTING.md
drwxr-xr-x 1 josep 197609       0 Apr  2 10:29 exercises/
-rw-r--r-- 1 josep 197609    1572 Apr  2 10:29 flake.lock
-rw-r--r-- 1 josep 197609    2032 Apr  2 10:29 flake.nix
-rw-r--r-- 1 josep 197609   42700 Apr  2 10:29 info.toml
-rwxr-xr-x 1 josep 197609    3116 Apr  2 10:29 install.ps1*
-rwxr-xr-x 1 josep 197609    4846 Apr  2 10:29 install.sh*
-rw-r--r-- 1 josep 197609    1117 Apr  2 10:29 LICENSE
-rw-r--r-- 1 josep 197609    6667 Apr  2 10:29 README.md
-rw-r--r-- 1 josep 197609    8996 Apr  4 07:56 rust-project.json
-rw-r--r-- 1 josep 197609     284 Apr  2 10:29 shell.nix
drwxr-xr-x 1 josep 197609       0 Apr  2 10:29 src/
drwxr-xr-x 1 josep 197609       0 Apr  2 10:29 target/
-rw-r--r-- 1 josep 197609 2748416 Apr  3 05:55 temp_104912_ThreadId1.pdb
-rw-r--r-- 1 josep 197609 2732032 Apr  2 20:19 temp_106948_ThreadId1.pdb
-rw-r--r-- 1 josep 197609 2748416 Apr  4 07:58 temp_37868_ThreadId1.pdb
-rw-r--r-- 1 josep 197609 2732032 Apr  2 11:49 temp_49388_ThreadId1.pdb
-rw-r--r-- 1 josep 197609 2732032 Apr  2 20:21 temp_54464_ThreadId1.pdb
-rw-r--r-- 1 josep 197609 2732032 Apr  2 20:21 temp_86324_ThreadId1.pdb
-rw-r--r-- 1 josep 197609 2732032 Apr  2 20:21 temp_88736_ThreadId1.pdb
-rw-r--r-- 1 josep 197609 1355776 Apr  2 10:31 temp_99564_ThreadId1.pdb
drwxr-xr-x 1 josep 197609       0 Apr  2 10:29 tests/

OS name and version: Windows 11 Pro, 22H2, Build 22621.1413

this is probably better suited for rust-lang/rust-analyzer but I'm still learning Rust 😓

[skycoop]

I am also having this issue with rust-analyzer v0.3.1472. Downgrading to v0.3.1451 solved the issue for me as well

[kin789246]

I also met this issue, rollback to v1451 can solve this for me on Windows 11, but MACOS VENTURA doesn't have this issue.

[thespeck]

Well, I'm not the only one having this problem. Can we expect a fix soon?

[shadows-withal]

It's not an issue on our end, the rust-project.json specification hasn't changed afaik (if it did, it'd break on non-Windows platforms as well). I'm not sure what the rust-analyzer developers' timeline or understanding of this issue is, though.

[shadows-withal]

Seems like https://github.com/rust-lang/rust-analyzer/issues/14663 has been posted, backlinking it here to help those in that issue.

[Lexey40o]

Found this after banging my head against the wall for a couple of hours thinking that I'm doing something wrong with rust-project.json or the rust-analyzer vscode plugin. Rolling back to v0.3.1451 fixed this for me too. Thank you! ❤️

[Veykril]

So I'm looking into this right now, a simple fix for your side would be to make the root_module entries in the generated rust-project.json absolute paths. (digging into why this broke from our side as well though, seems a bit odd)

Okay the cause is that the canonicalization screws with our VFS, unsure what we will do here, so I recommend that your json generator should emit absolute paths for everything for now.

[shadows-withal]

@Veykril that sounds like a good workaround for now, many thanks to you and @matklad for debugging this issue :)

[shadows-withal]

Fixed on main in 9508e97, will push a release ~today.

[Lexey40o]

Thanks for the 5.5.0 release @shadows-withal!

Using v0.3.1514 of the rust-analyzer vscode plugin (this latest version is only available on GitHub Releases as of writing) and 5.5.0 of Rustlings the issue appears to still be present.

Here are some details of my system:

Item	Value
rustlings --version	v5.5.0
rust-analyzer	v0.3.1514
rustc --version	rustc 1.69.0 (84c898d65 2023-04-16)
Operating System	Windows 10 Home, version 22H2, build 19045.2965

After running rustlings lsp I can see that the root_module path values in rust-project.json are absolute. Here's one for example:

"\\\\?\\C:\\Users\\<user>\\source\\repos\\rustlings\\exercises\\vecs\\vecs2.rs"

It's a little unexpected because I thought this rust-analyzer fix would've solved it if the 5.5.0 rustlings release didn't.

[shadows-withal]

@Lexey40o Weird! I'll pass it on.

[Veykril]

Ah, the problem is the UNC path I believe (the \\\\?\\ prefix). Our VFS will have a non UNC path indexed so it won't be able to resolve this properly. I assume you are using rust's path canonicalize function somewhere to get the absolute path which unfortunately returns UNC paths on windows ... That said, and I am sorry for not having brought that up here again afterwards but relative paths should just work again. We effectively ended up reverting the changes and took a stance for the current behavior now (as before we weren't sure which one we really wanted to stick with).

There is no decent way for us to handle different paths pointing to the same thing here unfortunately, s owe can't really do anything about unc paths and just opt to not support them currently.

[Lexey40o]

@Veykril gotcha!

Reverted back to rustlings 5.4.1 and its rustlings lsp generation is working with rust-analyzer v0.3.1514.

[shadows-withal]

That said, and I am sorry for not having brought that up here again afterwards but relative paths should just work again.

Ah okay, that's fine, I'll revert that change and push a patch version. Thanks for letting us know!

[shadows-withal]

@Lexey40o could you confirm it works again with Rustlings 5.5.1?

[Lexey40o]

@shadows-withal it sure is! Reran rustlings lsp with rustlings 5.5.1 and it's generating relative paths again, which looks to be working with rust-analyzer v0.3.1514. Thanks for the patch! 🎉

[shadows-withal]

Perfect, closing it for real now

[jiangyixin2001]

rustlings lsp work for me in rustlings 5.5.1 and 5.4.1. It is problem about rust-analyzer. I have change rust-analyzer v0.3.1506 to rust-analyzer v0.4.1522 Pre-Release, it is work!

[addisonjones3]

Hi all,

Trying rustlings out and this bug is happening to me in 5.6.1.

Relevant information: OS: Ubuntu 22.04 rustlings: 5.6.1 rustc --version: rustc 1.74.0 (79e9716c9 2023-11-13) rust-analyzer extension: Bug in both

• v0.3.1748
• v0.4.1753 (pre-release)

Steps to replicate:

• Install rustlings
• Run rustlings lsp
• In VS Code attempt command pallet command rust-analyzer: Restart server (no change)
• Restart VS Code (no change)

Any other steps anyone can think of?