Xcode 4.2 Release Notes

Xcode 4.2 Release Notes

Installation

• You can install Xcode 4.2 for OS X v10.6 Snow Leopard only if you have purchased an earlier release of Xcode.
  Install or update Xcode through the Purchases or Updates panes.
• If you purchased Xcode from the Mac App Store, the Install Xcode app is on the volume on which you installed Xcode.
  To install Xcode 4.2 on another volume, you must delete all copies of the Install Xcode app from your file system.

Xcode

• In Xcode 4.2 with iOS 5, support for running and debugging applications in the iOS 4.3 Simulator and on devices with iOS versions older than 4.2 is optional and installed only on demand. In addition, this support is no longer shipped as part of the core tools packaging, and is instead made available for download and installation through the "Downloads" pane of the Xcode Preferences panel. A valid iOS developer ADC account is required to obtain this content.
  To obtain the iOS 4.3 Simulator, choose More Simulators from the Run Destinations popup in the main toolbar. This item presents the Downloads pane of the Preferences and includes UI to initiate the installation of the simulator.
  To obtain iOS device support for pre-iOS 4.2 devices, connect a device and activate it for development in the Organizer. Xcode prompts you to initiate the download of the device support components.
  If Xcode 4.2 in iOS 5 is installed over a previous Xcode 4.2 beta or over Xcode 4.1, the iOS 4.3 Simulator and device support from the previous install will already be present, and the additional components will display as "Installed" in the Downloads pane of the Xcode Preferences.
  The installation packages for the downloaded components are stored in ~Library/Developer/Xcode. When a new version of Xcode (beta or GM) is installed, subsequent requests to install these components use the local packages without requiring a new download.
• In some cases, Xcode 4.2 Organizer does not display a device that is in restore mode. As a workaround you can use iTunes to restore.
• In iOS 5, iOS Simulator is not compatible with previous releases of the iCloud Developer Seed for OS X. It is highly recommended that you update to the latest iCloud Developer Seed to ensure compatibility.
• The iOS 5 SDK supports both iOS 4.3 and iOS 5.0 simulators.
• Be sure to quit any running Xcode before starting the uninstall-devtools script.
• The Network Link Conditioner daemon cannot be launched after installing the Networking Link Conditioner preference pane without first rebooting the system. As a result, the tool will not function without a system reboot.
  If you do not want to reboot the system, you can issue the following command from Terminal instead: sudo launchctl load /system/library/launchdaemons/com.apple.networklinkconditioner.plist
• If you are using multiple tabs in Xcode 4.2, some behaviors that are dependent on the Run Generates Output and Run Completes events may not get triggered. This bug will be fixed in future versions.

Interface Builder

• When initiating a refactoring rename operation from the declaration of a property, any Interface Builder files that refer to that property will not be updated correctly. Instead, perform the rename operation on a usage of the property, or an associated @synthesize statement.
• In Xcode 4.2, when copying views (either a single view or multiple views), both the user defined constraints on the selected view and the user defined constraints between the views are copied to the pasteboard.
• When developing Mac apps, changing the segment style of an NSSegmentedControl object to Automatic might crash in documents using Cocoa Auto Layout. To workaround the issue use an explicit segment style such as Round or Textured, and at runtime, change the segment style to automatic using the setSegmentStyle: method.

Instruments

• There is a known issue with the Profile action from Xcode 4.2. After a build in which no source files have changed, Instruments will be unable to gather symbols for the target application.
  This affects projects where both:
  1. The Release configuration is selected for the Profile action. (default)
  2. The Strip Linked Product build setting is set to "Yes”, or a custom Run Script build phase strips the product. (non-default)
  The workaround is to do any one of the following:
  1. Perform a "Clean" on the product before initiating the Profile action.
  2. Do a Clean of the product and temporarily set the Strip Linked Product build setting to "No" while Profiling.
  3. Set the configuration of the Profile action to Debug.
  4. Run successive profiles directly from within Instruments when you do not need to rebuild.
• When developing Mac apps, using the GC Monitor template in Instruments may cause Instruments to crash. To workaround the problem please consider migrating your application to ARC.

iOS Simulator

• When running Mac OS 10.7, Location Services are not functional in iOS simulator when simulating iOS 4.3 and earlier. This issue is not present when running Mac OS 10.6 or when simulating iOS 5.0.