How to debug Rust in Helix?

"Life is all about sharing. If we are good at something, pass it on." - Mary Berry

How to debug Rust in Helix?

2023-08-10

Helix supports debugging Rust by default using lldb-vscode. However, there is an issue where string variables are displayed as memory addresses instead of their actual values:

lldb-vscode - string variables memory addresses

Noticing that CodeLLDB natively supports visualization of most common Rust data types, I would like to give it a try.

Here’s the step-by-step process:

Download the CodeLLDB extension:

$ cd ~/Downloads/
$ wget https://github.com/vadimcn/codelldb/releases/download/v1.9.2/codelldb-aarch64-darwin.vsix

Setup the extension:

$ mkdir -p ~/.local
$ set fish_user_paths /Users/quantong/.local/extension/adapter $fish_user_paths
$ codelldb

If you encountered this error:

$ codelldb
Error: "\"dlopen(/Users/quantong/.local/extension/lldb/lib/liblldb.dylib, 0x0009): 
tried: \\'/Users/quantong/.local/extension/lldb/lib/liblldb.dylib\\' (code signature in <71492E0A-B915-3776-BCB8-266C07A85228> 
\\'/Users/quantong/.local/extension/lldb/lib/liblldb.dylib\\' not valid for use in process: library load disallowed by system policy)\""

Remove attributes using xattr:

$ xattr -cr ~/.local/extension/

Retry launching:

$ codelldb --port 13000

Switch to use codelldb by adding the following to ~/.config/helix/languages.toml:

[[language]]
name = "rust"

[language.debugger]
command = "codelldb"
name = "codelldb"
port-arg = "--port {}"
transport = "tcp"

[[language.debugger.templates]]
name = "binary"
request = "launch"

[[language.debugger.templates.completion]]
completion = "filename"
name = "binary"

[language.debugger.templates.args]
program = "{0}"
runInTerminal = false

$ hx --health rust
Configured language server: rust-analyzer
Binary for language server: /opt/homebrew/bin/rust-analyzer
Configured debug adapter: codelldb
Binary for debug adapter: /Users/quantong/.local/extension/adapter/codelldb
Highlight queries: ✓
Textobject queries: ✓
Indent queries: ✓

Create a new cargo package:

$ cargo new hello_cargo

Open src/main.rs and add the following code:

fn main() {
    let s = "world";
    let x = 2;
    let b = true;
    println!("Hello, {} {} {}!", s, x, b);
}

Build your code by running:

$ cargo build

The executable will be places in the target/debug directory.

In the Helix editor, use the following steps for debugging:

Press <Space> and then g to go to Debug.
Press b to toggle breakpoint.
Press l to launch debug target.
Enther the binary path target/debug/hello_cargo and press Enter.

After a few seconds, you’ll see the actual value of string variables:

codelldb - string variables values

Tags: helix dap lldb-vscode codelldb

Edit on GitHub