VSCode rust-analyzer and `cargo watch -x run` recompile when saving

Hi there,

I have a weird problem: whenever I use VSCode with rust-analyzer to work on a project, cargo watch -x run recompiles several dependencies. And the other way round: whenever cargo watch -x run recompiles the project, VSCode rust-analyzer has to recompile the project on save.

When I don't use VSCode Rust Analyzer and edit the Code e.g. with NeoVim (with a working rust-analyzer setup), this does not happen. When I use VS Code but do not start cargo to compile the project, it doesn't happen.

I checked if there might be different toolchain versions, but I have no other toolchain installed but the current stable.

And now I am baffled.

What am I doing wrong?

Best regards,
CK

This can happen if you have some custom RUSTFLAGS set (by env or config file) and either

  • The flags differ between the two builds, or
  • One build is a cross-compilation (--target specified) and the other is not

Make the flags the same, and if you are using --target, include it in the arguments to both, even if that means specifying the current machine's target triple.