workspace-lsp-roots is not used when opening a new document under the same language server

[sysheap]

Summary

I have set up a POC which illustrates the bug.
The POC can be found here: https://github.com/hieronymusma/poc-helix-workspace-lsp-roots/

My crate has the following structure
workspace-crate (actual rust workspace crate)
- crate1 (part of rust workspace crate, host target)
- crate2 (not part of the rust workspace crate, different target)

Because crate2 has a different target than the workspace crate, I need to setup workspace-lsp-roots (to ["./", "./crate2"]).

Now I get the following behavior:

If I first open crate2/main.rs and then crate1/main.rs everything works fine. Rust-analyzer starts and annotates for me the variables which are unused (that's how I test if it works or not).

However, If I switch it around and first open crate1/main.rs and then crate2/main.rs I loose the annotations of crate2.

I dug into the source code, and it seems that the root_dirs argument of find_lsp_workspace is the problem. If I'm using the problematic order (first crate then crate2), root_dirs is always an empty array. The value is taken from editor::Config::workspace_lsp_roots which is always an empty Vector. It never gets set.

I already have a working fix. However, I'm not familiar with the codebase at all. So I'm not sure if my fix is correct. I will link it under this issue in a couple of minutes. Maybe we can discuss the technical sides of the PR inside the PR then.

Thank you already for your time!

Reproduction Steps

1. git clone https://github.com/hieronymusma/poc-helix-workspace-lsp-roots/
2. cd poc-helix-workspace-lsp-roots
3. rustup component add rust-analyzer

Test case which works fine:
Open helix and first open crate2/src/main.rs via the file picker. Wait until rust-analyzer has done it's work, and then you will see a yellow annotation, that the info variable is unused. After that, open crate1/src/main.rs, wait again for the rust-analyzer, and then you will see that the variable unused is annotated.

Test case which doesn't work:
Now do the opposite. Open helix and first open crate1/src/main.rs. You will also see the yellow annotations. Then open crate2/src/main.rs. Wait a while and nothing happens. rust-analyzer is not running on this file.

Helix log

I compared both logs and the following line appears in the working version but not in the not-working version. That's also how I found the right spot in the source code.

difference.log

2024-12-09T17:30:31.640 helix_lsp::transport [INFO] rust-analyzer -> {"jsonrpc":"2.0","method":"workspace/didChangeWorkspaceFolders","params":{"event":{"added":[{"name":"poc-helix-workspace-lsp-roots","uri":"file:///home/hieronymusma/src/poc-helix-workspace-lsp-roots"}],"removed":[]}}}

Platform

Linux

Terminal Emulator

GNOME Terminal 3.52.0 using VTE 0.76.0 +BIDI +GNUTLS +ICU +SYSTEMD

Installation Method

snap

Helix Version

helix 24.7 (079f544)

[sysheap]

Nobody interested in merging this?

[TornaxO7]

I would rather think that the maintainers are quite busy at the moment, so don't worry.