VSCode setting to specify path to Cargo.toml

[oxalica]

Sometimes Cargo.toml is not in the workspace root, instead, inside some sub-directory.
Since the project contains non-rust code, it is not good idea to always create Cargo.toml workspace file in the root.

Is there any way to specify the directory or path to Cargo.toml processed by rust-analyzer?

[edwin0cheng]

Is there any way to specify the directory or path to Cargo.toml processed by rust-analyzer?

If I understand correctly, there is still no way to do that: see #2533

[matklad]

Yeah, there's no such setting (yet), it should be not that hard to add.

[menoude]

@matklad do you know if this is on the roadmap? I can try to implement it if not (and if it happens to be simple). Sadly this is what keeps our team from using rust-analyzer!

[matklad]

Sure, a PR would be welcome!

Here's the current code for determining the set of projects to analyze:

https://github.com/rust-analyzer/rust-analyzer/blob/61cb87e50629f510c8a1231102ba66ded524bec2/crates/rust-analyzer/src/bin/main.rs#L74-L82

[matklad]

Fixed in today's release:

{
    "rust-analyzer.linkedProjects": [
        "/home/matklad/tmp/hello/Cargo.toml"
    ]
}

(you can link more than one project)

[azzamsa]

Fixed in today's release:

{
    "rust-analyzer.linkedProjects": [
        "/home/matklad/tmp/hello/Cargo.toml"
    ]
}

(you can link more than one project)

How to achieve the same thing in Emacs? Other than using rust-project.json. I don't find it in the manual

[matklad]

@azzamsa tbh, I don't know how to pass settings to lang servers via lsp mode. I guess it should be documented somewhere here: https://emacs-lsp.github.io/lsp-mode/.

A PR to rust-analyzer's manual clarifying this would help!

[flodiebold]

There are specific emacs defcustoms for most settings. Probably not for linkedProjects though (can't check, not at my computer), and I don't know if it makes sense to handle it that way since it would always have to be defined with dir-locals... Might be worth opening an issue about there.

[zqyzsj]

Is this problem solved? I don't know how to specify the root of a non-standard cargo project in emacs.

[flodiebold]

You should be able to use lsp-rust-analyzer-linked-projects in a dir-local.

[zqyzsj]

You should be able to use lsp-rust-analyzer-linked-projects in a dir-local.

I tested the lsp-rust-analyzer-linked-projects config in my emacs config file, and it works. But it seems that I only can set a fixed path in the emacs config file. So if I open another rust project I need to change the emacs config file, which is strange. Is there any way to automate set the path of the cargo.toml?
Following is my config of lsp-rust-analyzer-linked-projects:
(lsp-rust-analyzer-linked-projects ["/my/path/to/some/project's/Cargo.toml"])

[flodiebold]

That's why you should set it in .dir-locals.el, not globally 🙂

[zqyzsj]

Thanks @flodiebold . I'll try it.

[yhslai]

How to specify this in emacs? The above comments mentioned lsp-rust-analyzer-linked-projects, but what's the equivalent to eglot?