退出并重新启动，退出并重新启动，...，多次。我得到了如下所示的日志：
Process: Xcode [1156]
Path: /Users/USER/Desktop/Xcode.app/Contents/MacOS/Xcode
Identifier: com.apple.dt.Xcode
Version: 4.5 (1839)
Build Info: IDEApplication-1839000000000000~3
Code Type: X86-64 (Native)
Parent Process: launchd [150]
User ID: 502
Date/Time: 2012-09-25 21:02:15.533 +0800
OS Version: Mac OS X 10.8 (12A269)
Report Version: 10
Interval Since Last Report: 1620650 sec
Crashes Since Last Report: 66
Per-App Interval Since Last Report: 209706 sec
Per-App Crashes Since Last Report: 62
Anonymous UUID: 410E9490-9BA7-4C02-8213-2D855F72E50B
Crashed Thread: 1 Dispatch queue: com.apple.root.default-priority
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Application Specific Information:
ProductBuildVersion: 4G182
ASSERTION FAILURE in /SourceCache/IDEFoundation/IDEFoundation-1877/Framework/Classes/Model/SourceControl/IDESourceControlWorkspaceMonitor.m:1054
Details: Attempted to add repository (IDESourceControlRepository) Name:xuexi@192.168.0, Type:Subversion,
Location:svn://xuexi@192.168.0.109 when (IDESourceControlRepository) Name:xuexi@192.168.0,
Type:Subversion,
Location:svn://xuexi@192.168.0.109 already existed.
Object: <IDESourceControlWorkspaceMonitor: 0x408e59140>
Method: -_findWorkingTreesForFilePath:
Thread: <NSThread: 0x40937d480>{name = (null), num = 11}
Hints: None
Backtrace:
0 0x00000001075167ef -[IDEAssertionHandler handleFailureInMethod:object:fileName:lineNumber:messageFormat:arguments:] (in IDEKit)
1 0x00000001067e02a5 _DVTAssertionFailureHandler (in DVTFoundation)
2 0x0000000107073cfd __block_global_5 (in IDEFoundation)
3 0x00007fff93f9acac -[NSBlockOperation main] (in Foundation)
4 0x00007fff93f70bb6 -[__NSOperationInternal start] (in Foundation)
5 0x00007fff93f783d1 __block_global_6 (in Foundation)
6 0x00007fff8c07bf3d _dispatch_call_block_and_release (in libdispatch.dylib)
7 0x00007fff8c0780fa _dispatch_client_callout (in libdispatch.dylib)
8 0x00007fff8c07923e _dispatch_worker_thread2 (in libdispatch.dylib)
9 0x00007fff942f6ceb _pthread_wqthread (in libsystem_c.dylib)
10 0x00007fff942e11b1 start_wqthread (in libsystem_c.dylib)
objc[1156]: garbage collection is ON
abort() called
真的需要帮助！