codeintel: add root to rust autoindex inferrence

[Strum355]

Address issues found for this auto-index job. There is the "danger" that it only catches the demo projects, but this is a step in the right direction

[sourcegraph-bot]

Notifying subscribers in CODENOTIFY files for diff c7f9aea...048726a.

Notify	File(s)
@efritz	lib/codeintel/autoindex/inference/rust.go lib/codeintel/autoindex/inference/rust_test.go

[Strum355]

@varungandhi-src I had to fix a test here but Im wondering why there was dir1 but the index job wasn't rooted at that.

[efritz]

Should we merge this?

[varungandhi-src]

I had to fix a test here but Im wondering why there was dir1 but the index job wasn't rooted at that.

Because I thought it didn't matter. rust-analyzer will find any nested Cargo.toml files and index the crates correctly. I've written a longer comment in https://github.com/sourcegraph/lsif-rust/blob/main/lsif-rust :

# rust-analyzer's path lookup looks in subdirectories by default. For example,
# in the general case, if you have multiple parallel workspaces, under say
# - A/B/C with crates X1, X2
# - A/B/D with crates Y1, Y2
# and you run rust-analyzer with A/ as the project path, it will pick up all
# crates (X1, X2, Y1 and Y2). So it is enough to run rust-analyzer once,
# instead of once per workspace, or once per crate.

Taking a look at the failed job...

[varungandhi-src]

I think this patch will actually create a regression, because the loop exits on the first match. So it won't emit multiple index jobs for the https://github.com/Picovoice/rhino repo, just one at the most. Also, I don't think it's just a matter of fixing the early exit because we should be able to handle workspaces... (naively picking up all Cargo.toml files will end up indexing crates twice.)

I think we should land a fix in lsif-rust itself, which can handle the path checking logic and keep this simple. I can submit a patch for that.

[varungandhi-src]

Oh sorry, I just realized this patch is ~21 days old. Somehow I just missed it. My bad. 🙇