Queue Debugging

  • Xcode 6 can show backtraces for enqueued blocks across GCD queues and threads in the Debug navigator.
  • In the Queues view, it also shows the pending blocks for a queue in addition to the blocks that are already executing.
    • Debug menu > Debug Workflow > Always Show Pending Blocks in Queue
  • Shortcut: hold down Option key and click the disclosure triangle to the left of the process info to expand all the thread backtraces.

View Debugging

  • View debugger button is on the Debug toolbar (bottom of the window) to the left of the “Simulate location” button.
  • Third view mode in the Debug navigator (in addition to thread and queue views) for showing the UI hierarchy.
    • You can filter views using the search field!
  • Attributes inspector shows view attributes but they are read-only.
  • Size inspector shows a list of all the layout constraints.

Integrating with Quick Look

  • Xcode 6 supports Quick Look for UIView and NSView.
  • Override -debugQuickLookObject in your own objects and return one of the supported types to add support for Quick Look.
  • More documentation here.