Types not inferred for some arguments in function call hint e.g. Option<_>

[jamesmcm]

Hi,

See this example: https://i.imgur.com/ISVhf2B.png

This is with rust-analyzer built from the master branch of this repo, and using coc-rust-analyzer in neovim.

The full function signature is:

fn send_email(
    recipient: &str,
    subject: &str,
    plain_body: &str,
    html_body: Option<&str>,
    attachment: Option<Attachment>,
    ses_client: &SesClient,
    rt: &mut tokio::runtime::Runtime,
) -> Result<()> 

defined in the same source file.

Where Result there is anyhow::Result

It fails to show the types for both Option<_> cases.

I'd be happy to contribute but I'm not sure where to start, even for just getting debug info when using coc and neovim on Linux.

Looking at the code, it seems the relevant part might be the lowering to LSP types in hir_ty/src/lower.rs.

[bjorn3]

Do you have the rust-src rustup component installed?

[jamesmcm]

Yep:

[18:36] archie | rustup component list
cargo-x86_64-unknown-linux-gnu (installed)
clippy-x86_64-unknown-linux-gnu (installed)
llvm-tools-preview-x86_64-unknown-linux-gnu
miri-x86_64-unknown-linux-gnu
rls-x86_64-unknown-linux-gnu
rust-analysis-x86_64-unknown-linux-gnu
rust-analyzer-preview-x86_64-unknown-linux-gnu
rust-docs-x86_64-unknown-linux-gnu (installed)
rust-src (installed)

[flodiebold]

This does look like rust-analyzer can't find the standard library. If you do something like

fn main() {
    let x = Some(1);
    x.
}

do you get completions? I'd guess not.

Do you have RUST_SRC_PATH set? Are you seeing any error messages in the rust-analyzer logs?

[jamesmcm]

Fixed: https://i.imgur.com/4TyFbdI.png

So the issue was I had some old settings from RLS, that were interfering. So I just removed the setting for RUST_SRC_PATH entirely and now it's okay.

Strangely rust-src didn't install to ~/.rustup/toolchain/TOOLCHAIN/lib/rustlib/src/rust/src but instead to like ~/.rustup/toolchain/TOOLCHAIN/lib/rustlib/src/rust/library - is that a change from the past?

[jamesmcm]

But for future reference, how can I check the rust-analyzer logs in cases like this?

[lnicola]

See #5586.

I'm not sure where the logs show up in vim, Code has a tool window for them.

[jamesmcm]

Thanks! I'll close this now.