ob / rust-sample

Repro for a VS Code or rust-analyzer bug

This is a minimal repro for a bug in VS Code or rust-analyzer. I'm not sure whether the bug is in cargo, rust-analyzer, or the VS Code extension.

What happens is that when you have a procedural macro that prints to stdout, and then you try to modify the place where the macro is invoked, the editor will hang.

Here's a screenshot of the hang:

In order to reproduce the bug, you need to do the following:

• Open the project in VS Code
• Open macros/src/lib.rs
• Uncomment the println! line
• Open src/main.rs
• Start editing the call to the sample_macro macro, you should see the editor hang.

The "Rust Analyzer Language Server" log shows the following:

Error: Custom { kind: InvalidData, error: Error("unknown variant `ApiVersionCheck`, expected `ListMacros` or `ExpandMacro`", line: 1, column: 18) }

The Rust Analyzer extension version is v0.4.1397.