"unresolved import"

[tigregalis]

I'm using Windows 10 Home version 1903, and Visual Studio Code 1.50.0, and rust-analyzer VS code extension version 0.2.344. I wasn't able to work out how to find the version of ra_lsp_server that's running.

I've seen this problem in a clone of the bevy repo at https://github.com/bevyengine/bevy . I'm seeing the below error in my "Problems" pane, but the project compiles fine (and using cargo check in the terminal doesn't warn us about anything).

bevy_math::Vec4 is ultimately a re-export of glam::f32::Vec4, but it sits alongside bevy_math::Vec3 which is ultimately a re-export of glam::f32::Vec3 which it doesn't have a problem resolving.

I've tried:

• restarting VS code - doesn't fix it
• tried changing the order of the use lines to trigger a re-check - doesn't fix it, which means it doesn't look like these are "stale" as per VS Code problem list is stale, even after "Rust Analyzer: Restart Server" #4073, but that cargo check is finding a problem in rust-analyzer, but not in the terminal
• tried changing the order of Vec4 vs Vec3 to trigger a re-check - rust-analyzer continues to point to Vec4 being unresolved, now in its new position, confirming this isn't "stale"
• I also tried "Restart Window" from the command palette in vain hopes (following on from VS Code problem list is stale, even after "Rust Analyzer: Restart Server" #4073)
• cloning a fresh copy of https://github.com/bevyengine/bevy - I changed any line in crates\bevy_render\color.rs and saved it, which reproduced this behaviour

Having opened my local copy of the glam source in my .cargo, I'm now seeing the behaviour there.

Other issues that may or may not be related: #6258, #6063, #6038

I was able to trivially reproduce this - see repo https://github.com/tigregalis/glam-breaks-ra:

[Veykril]

Looks like glam's Vec4 uses cfg attributes to determine the definition of the struct: https://github.com/bitshifter/glam-rs/blob/121cfaaa56494993d1666468039b2da663fd9a06/src/f32/vec4.rs#L21-L42
But it doesn't do that for Vec3: https://github.com/bitshifter/glam-rs/blob/121cfaaa56494993d1666468039b2da663fd9a06/src/f32/vec3.rs#L10-L13
So I imagine that is the problem.

[bjorn3]

https://github.com/bitshifter/glam-rs/blob/d1b83da533c5ddb161f2da4d76faa33607d59c67/build.rs#L16

That cfg is set by the build script. I don't think rust-analyzer has support for this.

[lnicola]

Shouldn't they work by https://github.com/rust-analyzer/rust-analyzer/blob/1b3b8c7/crates/project_model/src/cargo_workspace.rs#L314-L326 (if rust-analyzer.cargo.loadOutDirsFromCheck is set)?

[lnicola]

@tigregalis can you try enabling rust-analyzer.cargo.loadOutDirsFromCheck? This seems to work for me.

[tigregalis]

@lnicola That's solved it, thanks. What is this rust-analyzer.cargo.loadOutDirsFromCheck option doing?

@Veykril If I had to guess, the types that have those cfg attributes are the ones that (can) have SIMD support.

[lnicola]

It enables build script support, which makes those #[cfg]s work -- and also code generated at build-time, like other projects have.

[tigregalis]

Ok, thanks. I'll close the issue. It could be worth documenting though.

[a74731248]

@tigregalis can you try enabling rust-analyzer.cargo.loadOutDirsFromCheck? This seems to work for me.

Could you please tell me how to enable this？

[flodiebold]

It's called rust-analyzer.cargo.buildScripts.enable nowadays and enabled by default.