Rust Tauri Debugging Debugging techniques for Tauri applications with Rust backend. ## When to Use - Tauri app crashes or doesn't start - IPC commands failing or returning errors - State management issues - WSL2-specific Tauri problems - Build or bundling errors ## Quick Diagnosis ### App Won't Start 1. Check console output: ``bash # Run with debug output RUST_LOG=debug cargo tauri dev ` 2. **Check for GTK/WebKit issues** (WSL2): `bash export GDK_BACKEND=x11 export WEBKIT_DISABLE_COMPOSITING_MODE=1 cargo tauri dev ` 3. **Check for missing dependencies**: `bash # Ubuntu/Debian sudo apt install libwebkit2gtk-4.1-dev libgtk-3-dev libayatana-appindicator3-dev librsvg2-dev ` ### IPC Issues 1. **Command not found**: - Verify function is in generate_handler! macro - Check function name matches exactly (no typos) - Ensure #[tauri::command] attribute present 2. **Serialization errors**: - Check types implement Serialize/Deserialize - Verify TypeScript types match Rust types - Use Result<T, String> for error handling 3. **Arguments not received**: - Check parameter names match between Rust and TypeScript - Ensure complex types are properly serialized ## Debugging Techniques ### Enable Logging `rust // src-tauri/src/main.rs fn main() { env_logger::Builder::from_env( env_logger::Env::default().default_filter_or("debug") ).init(); tauri::Builder::default() // ... } // In commands #[tauri::command] fn my_command(input: String) -> Result<String, String> { log::debug!("my_command called with: {}", input); // ... } ` ### DevTools Console `typescript // Frontend - check for invoke errors try { const result = await invoke('command_name', { arg: value }); console.log('Success:', result); } catch (error) { console.error('Invoke failed:', error); } ` ### Inspect IPC Messages `rust // Add to tauri.conf.json for dev { "build": { "devPath": "http://localhost:5173", "beforeDevCommand": "bun dev", "withGlobalTauri": true } } ` Then in browser console: `javascript window.__TAURI_IPC__ // Check if available ` ## Common Issues ### State Not Persisting **Problem**: State resets between command calls **Solution**: Use managed state properly: `rust use std::sync::Mutex; use tauri::State; struct AppState { data: Mutex<Vec<String>>, } #[tauri::command] fn add_item(item: String, state: State<'_, AppState>) -> Result<(), String> { let mut data = state.data.lock().map_err(|e| e.to_string())?; data.push(item); Ok(()) } fn main() { tauri::Builder::default() .manage(AppState { data: Mutex::new(Vec::new()), }) .invoke_handler(tauri::generate_handler![add_item]) .run(tauri::generate_context!()) .expect("error"); } ` ### Async Commands Blocking **Problem**: UI freezes during long operations **Solution**: Use async commands: `rust #[tauri::command] async fn long_operation() -> Result<String, String> { tokio::time::sleep(std::time::Duration::from_secs(2)).await; Ok("Done".to_string()) } ` ### Window Events Not Firing **Problem**: window.emit() not reaching frontend **Solution**: Check event name and ensure listener is registered first: `typescript // Frontend - set up listener BEFORE triggering backend import { listen } from '@tauri-apps/api/event'; const unlisten = await listen('my-event', (event) => { console.log('Received:', event.payload); }); // Only now trigger the backend action await invoke('start_operation'); ` `rust // Backend use tauri::Manager; #[tauri::command] fn start_operation(app: tauri::AppHandle) { // Emit to all windows app.emit_all("my-event", "payload").ok(); } ` ### File Dialog Not Working in WSL2 **Problem**: File dialogs crash or don't appear **Solution**: Use Tauri's dialog API with workarounds: `rust #[tauri::command] async fn pick_file() -> Result<String, String> { let path = tauri::api::dialog::blocking::FileDialogBuilder::new() .pick_file() .ok_or("No file selected")?; Ok(path.to_string_lossy().to_string()) } ` If still failing, use native Gtk dialogs or implement custom file picker. ## WSL2-Specific Debugging ### Check WebKitGTK Installation `bash pkg-config --modversion webkit2gtk-4.1 # Should return version number # If missing: sudo apt install libwebkit2gtk-4.1-dev ` ### Debug GTK Issues `bash GTK_DEBUG=interactive cargo tauri dev ` ### Check Display Configuration `bash echo $DISPLAY # Should be :0 for WSLg echo $WAYLAND_DISPLAY # Should be set for WSLg # Test with simple GTK app gtk3-demo ` ## Build Debugging ### Bundle Fails ``bash # Verbose b