rdjakovic/debugging-tauri-apps

Debugging Tauri Applications

This skill covers debugging Tauri v2 applications including console debugging, WebView inspection, IDE configurations, and CrabNebula DevTools.

Development-Only Code

Use conditional compilation to exclude debug code from production builds:

// Only runs during `tauri dev`
#[cfg(dev)]
{
    // Development-only code
}

// Runtime check
if cfg!(dev) {
    // tauri dev code
} else {
    // tauri build code
}

// Programmatic check
let is_dev: bool = tauri::is_dev();

// Debug builds and `tauri build --debug`
#[cfg(debug_assertions)]
{
    // Debug-only code
}

Console Debugging

Rust Print Macros

Print messages to the terminal where tauri dev runs:

println!("Message from Rust: {}", msg);
dbg!(&variable);  // Prints variable with file:line info

Enable Backtraces

For detailed error information:

# Linux/macOS
RUST_BACKTRACE=1 tauri dev

# Windows PowerShell
$env:RUST_BACKTRACE=1
tauri dev

WebView DevTools

Opening DevTools

• Right-click and select "Inspect Element"
• Ctrl + Shift + i (Linux/Windows)
• Cmd + Option + i (macOS)

Platform-specific inspectors: WebKit (Linux), Safari (macOS), Edge DevTools (Windows).

Programmatic Control

tauri::Builder::default()
    .setup(|app| {
        #[cfg(debug_assertions)]
        {
            let window = app.get_webview_window("main").unwrap();
            window.open_devtools();
            // window.close_devtools();
        }
        Ok(())
    })

Production DevTools

Create a debug build for testing:

tauri build --debug

To permanently enable devtools in production, add to src-tauri/Cargo.toml:

[dependencies]
tauri = { version = "...", features = ["...", "devtools"] }

WARNING: Using the devtools feature enables private macOS APIs that prevent App Store acceptance.

---

VS Code Setup

Required Extensions

| Extension | Platform | Purpose | |-----------|----------|---------| | vscode-lldb | All | LLDB debugger | | C/C++ | Windows | Visual Studio debugger |

launch.json Configuration

Create .vscode/launch.json:

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "lldb",
      "request": "launch",
      "name": "Tauri Development Debug",
      "cargo": {
        "args": [
          "build",
          "--manifest-path=./src-tauri/Cargo.toml",
          "--no-default-features"
        ]
      },
      "preLaunchTask": "ui:dev"
    },
    {
      "type": "lldb",
      "request": "launch",
      "name": "Tauri Production Debug",
      "cargo": {
        "args": [
          "build",
          "--release",
          "--manifest-path=./src-tauri/Cargo.toml"
        ]
      },
      "preLaunchTask": "ui:build"
    }
  ]
}

Windows Visual Studio Debugger

For faster Windows debugging with better enum support:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Launch App Debug",
      "type": "cppvsdbg",
      "request": "launch",
      "program": "${workspaceRoot}/src-tauri/target/debug/your-app-name.exe",
      "cwd": "${workspaceRoot}",
      "preLaunchTask": "dev"
    }
  ]
}

tasks.json Configuration

Create .vscode/tasks.json:

{
  "version": "2.0.0",
  "tasks": [
    {
      "label": "ui:dev",
      "type": "shell",
      "isBackground": true,
      "command": "npm",
      "args": ["run", "dev"]
    },
    {
      "label": "ui:build",
      "type": "shell",
      "command": "npm",
      "args": ["run", "build"]
    },
    {
      "label": "build:debug",
      "type": "cargo",
      "command": "build",
      "options": {
        "cwd": "${workspaceRoot}/src-tauri"
      }
    },
    {
      "label": "dev",
      "dependsOn": ["build:debug", "ui:dev"],
      "group": {
        "kind": "build"
      }
    }
  ]
}

Debugging Workflow

1. Set breakpoints by clicking the line number margin in Rust files
2. Press F5 or select debug configuration from Run menu
3. The preLaunchTask runs the dev server automatically
4. Debugger attaches and stops at breakpoints

NOTE: LLDB bypasses the Tauri CLI, so beforeDevCommand and beforeBuildCommand must be configured as tasks.

---

RustRover / IntelliJ Setup

Project Configuration

If your project lacks a top-level Cargo.toml, create a workspace file:

[workspace]
members = ["src-tauri"]

Or attach src-tauri/Cargo.toml via the Cargo tool window.

Run Configurations

Create two configurations in Run | Edit Configurations:

1. Tauri App Configuration (Cargo)

• Command: run
• Additional arguments: --no-default-features

The --no-default-features flag is critical - it tells Tauri to load assets from the dev server instead of bundling them.

2. Development Server Configuration

For Node-based projects:

• Create an npm Run Configuration
• Set package manager (npm/pnpm/yarn)
• Set script to dev

For Rust WASM (Trunk):

• Create a Shell Script configuration
• Command: trunk serve

Debugging Workflow

1. Start the development server configuration first
2. Click Debug on the Tauri App configuration
3. RustRover halts at Rust breakpoints automatically
4. Inspect variables and step through code

---

Neovim Setup

Required Plugins

• nvim-dap - Debug Adapter Protocol client
• nvim-dap-ui - Debugger UI
• nvim-nio - Async dependency for nvim-dap-ui
• overseer.nvim (recommended) - Task management

Prerequisites

Download codelldb from GitHub releases and note the installation path.

DAP Configuration

Add to your Neovim config (init.lua or equivalent):

local dap = require("dap")

-- Configure codelldb adapter
dap.adapters.codelldb = {
  type = 'server',
  port = "${port}",
  executable = {
    command = '/path/to/codelldb/adapter/codelldb',
    args = {"--port", "${port}"},
  }
}

-- Launch configuration for Rust/Tauri
dap.configurations.rust = {
  {
    name = "Launch Tauri App",
    type = "codelldb",
    request = "launch",
    program = function()
      return vim.fn.input('Path to executable: ', vim.fn.getcwd() .. '/target/debug/', 'file')
    end,
    cwd = '${workspaceFolder}',
    stopOnEntry = false
  },
}

UI Integration

local dapui = require("dapui")
dapui.setup()

-- Auto-open/close UI
dap.listeners.before.attach.dapui_config = function()
  dapui.open()
end
dap.listeners.before.launch.dapui_config = function()
  dapui.open()
end
dap.listeners.before.event_terminated.dapui_config = function()
  dapui.close()
end
dap.listeners.before.event_exited.dapui_config = function()
  dapui.close()
end

Visual Indicators

vim.fn.sign_define('DapBreakpoint', {
  text = 'B',
  texthl = 'DapBreakpoint',
  linehl = '',
  numhl = ''
})
vim.fn.sign_define('DapStopped', {
  text = '>',
  texthl = 'DapStopped',
  linehl = 'DapStopped',
  numhl = ''
})

Keybindings

vim.keymap.set('n', '<F5>', function() dap.continue() end)
vim.keymap.set('n', '<F6>', function() dap.disconnect({ terminateDebuggee = true }) end)
vim.keymap.set('n', '<F10>', function() dap.step_over() end)
vim.keymap.set('n', '<F11>', function() dap.step_into() end)
vim.keymap.set('n', '<F12>', function() dap.step_out() end)
vim.keymap.set('n', '<Leader>b', function() dap.toggle_breakpoint() end)
vim.keymap.set('n', '<Leader>o', function() overseer.toggle() end)
vim.keymap.set('n', '<Leader>R', function() overseer.run_template() end)

Development Server Task

Create .vscode/tasks.json for overseer.nvim compatibility:

{
  "version": "2.0.0",
  "tasks": [
    {
      "type": "process",
      "label": "dev server",
      "command": "npm",
      "args": ["run", "dev"],
      "isBackground": true,
      "presentation": {
        "revealProblems": "onProblem"
      },
      "problemMatcher": {
        "pattern": {
          "regexp": "^error:.*",
          "file": 1,
          "line": 2
        },
        "background": {
          "activeOnStart": false,
          "beginsPattern": ".*Rebuilding.*",
          "endsPattern": ".*listening.*"
        }
      }
    }
  ]
}

NOTE: The development server does not start automatically when bypassing Tauri CLI. Use overseer.nvim or start it manually.

---

CrabNebula DevTools

CrabNebula DevTools provides real-time application instrumentation including log inspection, performance monitoring, and Tauri event/command analysis.

Features

• Inspect log events (including dependency logs)
• Monitor command execution performance
• Analyze Tauri events with payloads and responses
• Real-time visualization

Installation

cargo add [email protected]

Setup

Initialize DevTools as early as possible in src-tauri/src/main.rs:

fn main() {
    // Initialize DevTools only in debug builds
    #[cfg(debug_assertions)]
    let devtools = tauri_plugin_devtools::init();

    let mut builder = tauri::Builder::default();

    #[cfg(debug_assertions)]
    {
        builder = builder.plugin(devtools);
    }

    builder
        .run(tauri::generate_context!())
        .expect("error while running tauri application")
}

Usage

When running tauri dev, DevTools automatically opens a web-based interface showing:

• Application logs with filtering
• IPC command calls with timing
• Event payloads and responses
• Performance spans

For full documentation, see CrabNebula DevTools docs.

---

Quick Reference

| Task | Command/Action | |------|----------------| | Enable backtraces | RUST_BACKTRACE=1 tauri dev | | Open WebView DevTools | Ctrl+Shift+i / Cmd+Option+i | | Debug build | tauri build --debug | | Add DevTools plugin | cargo add [email protected] |

IDE Comparison

| Feature | VS Code | RustRover | Neovim | |---------|---------|-----------|--------| | Extension/Plugin | vscode-lldb | Built-in | nvim-dap + codelldb | | Windows Alt | cppvsdbg | Built-in | codelldb | | Task Runner | tasks.json | Run configs | overseer.nvim | | Setup Complexity | Medium | Low | High |

Common Issues

1. Breakpoints not hit: Ensure --no-default-features is set when building
2. Dev server not starting: Configure preLaunchTask or start manually
3. App not loading frontend: Dev server must be running before Tauri app starts
4. Windows enum display issues: Use cppvsdbg instead of LLDB