Xcode 4.6.3が来てたので、ソフトウェア・アップデート経由でインストールしました。
• Fixes an issue where debugging in the iOS Simulator could hang on OS X 10.8.4.
Included in Xcode 4.6:
• Includes SDKs for OS X 10.8 Mountain Lion and iOS 6.1.
• Code completion heuristics are more accurate, and use an optimized default data set.
• New compiler warnings help identify potential bugs when using ARC and weak references.
• C++11 support for ‘user defined literals’ and ‘unrestricted unions’ features.
• Debugger can inspect elements within NSArray or NSDictionary objects.
• Analyze now performs deeper cross-function static analysis of Objective-C and C++ code.
• The number of indexing passes is reduced due to improved dependency checking.