False positive compilation errors using Rust

[adrianboston]

Issue Type: Bug

I get false positive compilation errors showing up in the "Problems" dropdown that seems to be an iterative real-time compile. Run/Debug works with no issue. Turning to terminal compiles with no errors.

It started very soon after adding unit tests into the source, using the #[test] pragma. Sometimes the error shows within commented code.

Prior to that, no issues.

Extension version: 0.7.8
VS Code version: Code 1.63.2 (Universal) (899d46d82c4c95423fb7e10e68eba52050e30ba3, 2021-12-15T09:37:28.172Z)
OS version: Darwin x64 17.7.0
Restricted Mode: No

System Info

Item	Value
CPUs	Intel(R) Xeon(R) CPU E5-2650 v2 @ 2.60GHz (32 x 2594)
GPU Status	2d_canvas: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	3, 3, 3
Memory (System)	64.00GB (4.40GB free)
Process Argv	--crash-reporter-id 3459ab68-b960-4433-b56f-adab7430e7a4
Screen Reader	no
VM	0%

A/B Experiments

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[lnicola]

@adrianboston your report isn't actionable. You should include at least a screenshot, the problematic code and maybe a reduced copy of it, which someone can paste into Code to reproduce the problem.

Having said that, you should try https://marketplace.visualstudio.com/items?itemName=matklad.rust-analyzer, see #927 for details. rust-analyzer too has false positive diagnostics and corner cases, but it is currently more actively maintained.

[adrianboston]

It is not reproducible. False positive shows up; then disappear. Its m-m-m-magic. I will endeavour to post some very short code that displays this behaviour. It's currently part of a large proj. Im using this rust although it states powered by rust analyzer. I found it very stable.

[lnicola]

Im using this rust although it states powered by rust analyzer.

It's not. It has an option for that, but it's been broken for one year and a half, I think.

I found it very stable.

It's all right if you like it, but the last commit in this repository is from February 2021. If you run into any issues, it's unlikely that they will be solved soon.

[adrianboston]

I found its nothing to do with particular code. The errors are one from a previous build. The error line number is sometimes within commented lines. The error and line number remains the same in the Problems area despite updates and changes.

A reboot of the window / project clears the window of the error, returning it to either a clean build or clear/refresh the Problem window.

Perhaps VS Code needs a "Clear" or "Refresh" facility by way of a button. Or a Trashcan symbol as found in terminal. That simply cleans, clears or refresh the last compilation.

[lnicola]

I mean, it's still worth trying rust-analyzer, since it will replace RLS at some point in the future. Issues reported here are unlikely to be addressed.

Beware of some missing functionality, though: the biggest one is that in rust-analyzer most diagnostics are recomputed after you save a file and not while typing.