Failed to discover workspace

Hi folks, thank you so much for making rust-mode, I use it every day together with rustic-mode.

I filled https://github.com/emacs-rustic/rustic/issues/110 yesterday, but the issue might actually belong here?

The tl;dr is that rust-analyzer isn't able to auto-discover the Cargo workspace if what Emacs/Eglot considers the projects root — computed with (project-root (project-current)) — doesn't match what Cargo considers the root.

By default, the Emacs project root is defined by the VCS folder, typically a .git directory. So this project layout works fine:

project/
  .git/
  Cargo.toml
  src/
    lib.rs

as does this layout since rust-analyzer recurses one level deep in its auto-discovery:

project/
  .git/
  rust/
    Cargo.toml
    src/
      lib.rs

However, this one fails:

project/
  .git/
  rust/
    foo/
      Cargo.toml
      src/
        lib.rs

I've added my own function to project-find-functions and it seems to work okay (see https://github.com/emacs-rustic/rustic/issues/110). I would love an expert to look it over, and if possible, include it in rust-mode or rustic-mode.

Feel free to close either issue since they're effectively duplicates of each other (I just didn't know where to file this).

Thanks!

Start with the project-find-functions customization and the related rustic-mode issue 110, then inspect how rust-mode and rustic-mode determine project roots for Cargo workspaces. Done means supporting the deeper workspace layout described here or clearly documenting why the proposed discovery function cannot be included.