Debugging Rust on Vscode : u8 not shown correctly

Question

I am debugging this simple Rust program on Vscode

fn main() {
    let u8: u8 = 3;
    let b: u16 = 5;
    let c: u32 = 7;
    let d: u64 = 9;
}

The values of these variables are displayed correctly, except for u8

I'm curious, is there a reason or a solution for this issue? Thank you!

Edit Here's my launch.json configuration. I also followed a tutorial and installed the C/C++ extension with "type": "cppvsdbg", but it gives me the same result.

I'm also adding that I am a Rust newbie :)

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "lldb",
      "request": "launch",
      "name": "Debug",
      "program": "${workspaceFolder}/<your program>",
      "args": [],
      "cwd": "${workspaceFolder}"
    }
  ]
}

---

Edit Thanks to @Unapiedra & @ChayimFriedman, for their answers and insights. I couldn't solve this problem. But here's what I tried, someone might pick it up in the future

1. I autogenerated launch.json (thx @Unapiedra)
2. Following this doc, I added this to my launch configuration

    "preRunCommands": [
        "type format add --format hex int" // This is a test from lldb.llvm.org/use/variable.html
      ]

But it didn't work. I also tried initCommands to no avail.

Answer 1

The reason this happens is because you are using the C++ extension not the Rust extension for the debugger.

LLDB or the debugger frontend in VSCode needs to guess the type of your a variable. And it interprets the byte to show it in hex formatting.

On my setup, it works out of the box. I posted my launch.json below. This was autogenerated by VsCode. I would guess that the RustAnalyzer extension is the driver of this.

The autogeneration was triggered by me clicking on the Debugging tab, then clicking on 'create a launch.json file'. And then I get a prompt that Cargo.toml has been detected and I can generate debug targets.

{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "lldb",
            "request": "launch",
            "name": "Debug executable 'q72117996'",
            "cargo": {
                "args": [
                    "build",
                    "--bin=q72117996",
                    "--package=q72117996"
                ],
                "filter": {
                    "name": "q72117996",
                    "kind": "bin"
                }
            },
            "args": [],
            "cwd": "${workspaceFolder}"
        },
        {
            "type": "lldb",
            "request": "launch",
            "name": "Debug unit tests in executable 'q72117996'",
            "cargo": {
                "args": [
                    "test",
                    "--no-run",
                    "--bin=q72117996",
                    "--package=q72117996"
                ],
                "filter": {
                    "name": "q72117996",
                    "kind": "bin"
                }
            },
            "args": [],
            "cwd": "${workspaceFolder}"
        }
    ]
}