How to solve the rust analyzer failure

VSCode extension

Rust is hot right now. Everyone wants to learn it, or at least that’s what they say. I’m in love with the language too, and recently I convinced myself that it would be a good idea to become a master at Rust. So I did the thing that always works whenever you’re trying to learn something technical: putting in keyboard time. You literally have to put your fingers on the keyboard and press the damn keys.

With Python being my first programming language, I knew learning Rust was not going to be a walk in the park. So I had to arm myself with anything that would make it easier to learn. A few searches for “How can I make learning Rust easier?” pointed me to the VSCode extension Rust Analyzer. I installed the extension, and it worked – until it didn’t.

The dreaded red highlight and x mark

You know Rust Analyzer isn’t working anymore when it shows up like this in your text editor:

rust analyzer not working

It turns out Rust Analyzer only works when the folders in your working directory are Rust projects. If any of your folders aren’t Rust projects, you’ll get the dreaded red highlight, and Rust Analyzer will fail.

How to solve the failure

Suppose you have a Parent-folder with subfolders Project-1 and Project-2. To make Rust Analyzer work, you’ll need to create a Cargo.toml file in Parent-folder and list the subfolders. First, the hierarchy of your folders should look like this:

Parent-folder
├── Project-1
│   ├── src
│   │   └── main.rs
│   └── Cargo.toml
├── Project-2
│   ├── src
│   │   └── main.rs
│   └── Cargo.toml
└── Cargo.toml   <-- workspace file

And here’s what the Cargo.toml in Parent-folder should look like:

[workspace]
members = [
    "Project-1",
    "Project-2"
]

When you save the Cargo.toml file, the Rust Analyzer status in your text editor will look like this:

rust analyzer working

This indicates that Rust Analyzer is now working properly.