Compilation and debugging in Flutter

--- description: Fix Dart analyzer errors and Flutter build failures incrementally. Invokes the dart-build-resolver agent for minimal, surgical fixes. --- # Flutter Build and Fix This command invokes the dart-build-resolver agent to incrementally fix Dart/Flutter build errors with minimal changes. ## What This Command Does 1. Run Diagnostics: Execute flutter analyze, flutter pub get 2. Parse Errors: Group by file and sort by severity 3. Fix Incrementally: One error at a time 4. Verify Each Fix: Re-run analysis after each change 5. Report Summary: Show what was fixed and what remains ## When to Use Use /flutter-build when: - flutter analyze reports errors - flutter build fails for any platform - dart pub get / flutter pub get fails with version conflicts - build_runner fails to generate code - After pulling changes that break the build ## Diagnostic Commands Run ``bash # Analysis flutter analyze 2>&1 # Dependencies flutter pub get 2>&1 # Code generation (if project uses build_runner) dart run build_runner build --delete-conflicting-outputs 2>&1 # Platform builds flutter build apk 2>&1 flutter build web 2>&1 ` ## Example Session ``text User: /flutter-build Agent: # Flutter Build Resolution ## Initial Diagnostics ` $ flutter analyze Analyzing project... error • lib/features/user/data/user_repository_impl.dart:34:16 • A value of type 'String?' can't be assigned to a variable of type 'String'. • invalid_assignment error • lib/features/cart/presentation/cart_page.dart:58:5 • The method 'add' isn't defined for the type 'List<Item>'. Try correcting the name to the name of an existing method, or defining a method named 'add'. • undefined_method 2 errors found. ` ## Fix 1: Null Safety File: lib/features/user/data/user_repository_impl.dart:34 Error: A value of type 'String?' can't be assigned to type 'String' Changed: `dart final id = response.id; ` To: `dart final id = response.id ?? ''; ` ` $ flutter analyze 1 error found. ` ## Fix 2: Immutable List File: lib/features/cart/presentation/cart_page.dart:58 Error: The method 'add' isn't defined for the type 'List<Item>' Cause: State holds an unmodifiable list; mutation goes through Cubit Changed: `dart state.items.add(item); ` To: `dart context.read<CartCubit>().addItem(item); // Note: Cubit exposes named methods (addItem, removeItem); // .add(event) is the BLoC event API : don't mix them. ` ` $ flutter analyze No issues found! ` ## Final Verification ` $ flutter test All tests passed. ` ## Summary | Metric | Count | |--------|-------| | Analysis errors fixed | 2 | | Files modified | 2 | | Remaining issues | 0 | Build Status: PASS ✓ `` ## Common Errors Fixed | Error | Typical Fix | |-------|-------------| | A value of type 'X?' can't be assigned to 'X' | Add ?? default or null guard | | The name 'X' isn't defined | Add import or fix typo | | Non-nullable instance field must be initialized | Add initializer or late | | Version solving failed | Adjust version constraints in pubspec.yaml | | Missing concrete implementation of 'X' | Implement missing interface method | | build_runner: Part of X expected | Delete stale .g.dart and rebuild | ## Fix Strategy 1. **Analysis errors first** : code must be error-free 2. **Warning triage second** : fix warnings that could cause runtime bugs 3. **pub conflicts third** : fix dependency resolution 4. **One fix at a time** : verify each change 5. **Minimal changes** : don't refactor, just fix ## Stop Conditions The agent will stop and report if: - Same error persists after 3 attempts - Fix introduces more errors - Requires architectural changes - Package upgrade conflicts need user decision ## Related Commands - /flutter-test : Run tests after build succeeds - /flutter-review : Review code quality - verification-loop skill : Full verification loop ## Related - Agent: agents/dart-build-resolver.md - Skill: skills/flutter-dart-code-review/`