gh-sjungling-claude-plugins-plugins-swift-engineer/skills/ios-swift-expert/references/debugging-strategies.md

Debugging Strategies

Comprehensive debugging techniques for iOS and macOS development.

Xcode Build Issues

1. Clean Build Folder: Product → Clean Build Folder (Cmd+Shift+K)
2. Delete Derived Data: rm -rf ~/Library/Developer/Xcode/DerivedData
3. Check Build Settings: Verify code signing, Swift version, deployment target
4. Read Error Carefully: Xcode errors often include fix-its
5. Check Dependencies: Swift Package Manager, CocoaPods, or Carthage issues

Runtime Issues

1. Breakpoints: Set symbolic breakpoints for exceptions
2. LLDB Commands: po, expr, frame variable for inspection
3. View Debugging: Use Xcode's visual debugger (Debug → View Debugging)
4. Memory Graph: Detect retain cycles with Debug → Memory Graph
5. Instruments: Profile with Time Profiler, Allocations, Leaks

SwiftUI Debugging

1. Preview Crashes: Check PreviewProvider initialization
2. State Updates: Verify state changes on main thread
3. View Redrawing: Use Self._printChanges() to debug updates
4. Modifiers Order: Order matters (frame before padding vs. padding before frame)