Xcode keeps crashing when I select source control > History

Question

My Xcode always crashes when I select Source Control > History. It's been happening for a long time, likely back to Xcode 6, and continuing through Xcode 7.2.

I have attached the log which shows up after the crash:

Process:               Xcode [31491]
Path:                  /Applications/Xcode.app/Contents/MacOS/Xcode
Identifier:            com.apple.dt.Xcode
Version:               7.2 (9548)
Build Info:            IDEFrameworks-9548000000000000~7
Code Type:             X86-64 (Native)
Parent Process:        ??? [1]
Responsible:           Xcode [31491]
User ID:               501

Date/Time:             2015-12-25 11:14:33.771 +0530
OS Version:            Mac OS X 10.11.2 (15C50)
Report Version:        11
Anonymous UUID:        C50FD82E-3542-C9C3-C7B0-90B2D1E16E02

Sleep/Wake UUID:       256EB97F-CE9F-4D43-88C6-07F3B53C923F

Time Awake Since Boot: 40000 seconds
Time Since Wake:       3600 seconds

System Integrity Protection: enabled

Crashed Thread:        0  Dispatch queue: IDESourceControlLogItemsLock

Exception Type:        EXC_CRASH (SIGABRT)
Exception Codes:       0x0000000000000000, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY

Application Specific Information:
ProductBuildVersion: 7C68
UNCAUGHT EXCEPTION (NSInvalidArgumentException): *** -[__NSCFCalendar components:fromDate:]: date cannot be nil
UserInfo: (null)
Hints: None
Backtrace:
  0  0x00007fff98884aca __exceptionPreprocess (in CoreFoundation)
  1  0x00000001091a9c67 DVTFailureHintExceptionPreprocessor (in DVTFoundation)
  2  0x00007fff8c98ff7e objc_exception_throw (in libobjc.A.dylib)
  3  0x00007fff987a517b -[__NSCFCalendar components:fromDate:] (in CoreFoundation)
  4  0x00007fff987a47fe -[_NSCopyOnWriteCalendarWrapper components:fromDate:] (in CoreFoundation)
  5  0x000000010a8dc54a __41-[IDESourceControlLog arrangeLogEntries:]_block_invoke (in IDEKit)
  6  0x00007fff9a14a33f _dispatch_client_callout (in libdispatch.dylib)
  7  0x00007fff9a14b926 _dispatch_barrier_sync_f_invoke (in libdispatch.dylib)
  8  0x00000001091e5005 DVTDispatchBarrierSync (in DVTFoundation)
  9  0x0000000108f7d627 -[DVTDispatchLock performLockedBlock:] (in DVTFoundation)
 10  0x000000010a4db06a -[IDESourceControlLog arrangeLogEntries:] (in IDEKit)
 11  0x000000010a8ddfd6 __109-[IDESourceControlLog loadLogItemsFromRevisions:searchString:searchType:incrementalLogBlock:completionBlock:]_block_invoke_2177 (in IDEKit)
 12  0x00000001091e5efa ___DVTAsyncPerformBlockOnMainRunLoop_block_invoke (in DVTFoundation)
 13  0x00007fff987944ac __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ (in CoreFoundation)
 14  0x00007fff98786165 __CFRunLoopDoBlocks (in CoreFoundation)
 15  0x00007fff9878592e __CFRunLoopRun (in CoreFoundation)
 16  0x00007fff98785338 CFRunLoopRunSpecific (in CoreFoundation)
 17  0x00007fff9a8dd935 RunCurrentEventLoopInMode (in HIToolbox)
 18  0x00007fff9a8dd677 ReceiveNextEventCommon (in HIToolbox)
 19  0x00007fff9a8dd5af _BlockUntilNextEventMatchingListInModeWithFilter (in HIToolbox)
 20  0x00007fff8d7ee0ee _DPSNextEvent (in AppKit)
 21  0x00007fff8dbba943 -[NSApplication _nextEventMatchingEventMask:untilDate:inMode:dequeue:] (in AppKit)
 22  0x00000001097840c2 -[DVTApplication nextEventMatchingMask:untilDate:inMode:dequeue:] (in DVTKit)
 23  0x00007fff8d7e3fc8 -[NSApplication run] (in AppKit)
 24  0x00007fff8d766520 NSApplicationMain (in AppKit)
 25  0x00007fff882df5ad start (in libdyld.dylib)

abort() called

Application Specific Signatures:
NSInvalidArgumentException

Application Specific Backtrace 1:
0   CoreFoundation                      0x00007fff98884ae2 __exceptionPreprocess + 178
1   DVTFoundation                       0x00000001091a9c67 DVTFailureHintExceptionPreprocessor + 194
2   libobjc.A.dylib                     0x00007fff8c98ff7e objc_exception_throw + 48
3   CoreFoundation                      0x00007fff987a517b -[__NSCFCalendar components:fromDate:] + 2315
4   CoreFoundation                      0x00007fff987a47fe -[_NSCopyOnWriteCalendarWrapper components:fromDate:] + 78
5   IDEKit                              0x000000010a8dc54a __41-[IDESourceControlLog arrangeLogEntries:]_block_invoke + 534
6   libdispatch.dylib                   0x00007fff9a14a33f _dispatch_client_callout + 8
7   libdispatch.dylib                   0x00007fff9a14b926 _dispatch_barrier_sync_f_invoke + 74
8   DVTFoundation                       0x00000001091e5005 DVTDispatchBarrierSync + 62
9   DVTFoundation                       0x0000000108f7d627 -[DVTDispatchLock performLockedBlock:] + 116
10  IDEKit                              0x000000010a4db06a -[IDESourceControlLog arrangeLogEntries:] + 147
11  IDEKit                              0x000000010a8ddfd6 __109-[IDESourceControlLog loadLogItemsFromRevisions:searchString:searchType:incrementalLogBlock:completionBlock:]_block_invoke_2177 + 56
12  DVTFoundation                       0x00000001091e5efa ___DVTAsyncPerformBlockOnMainRunLoop_block_invoke + 72
13  CoreFoundation                      0x00007fff987944ac __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
14  CoreFoundation                      0x00007fff98786165 __CFRunLoopDoBlocks + 341
15  CoreFoundation                      0x00007fff9878592e __CFRunLoopRun + 910
16  CoreFoundation                      0x00007fff98785338 CFRunLoopRunSpecific + 296
17  HIToolbox                           0x00007fff9a8dd935 RunCurrentEventLoopInMode + 235
18  HIToolbox                           0x00007fff9a8dd677 ReceiveNextEventCommon + 184
19  HIToolbox                           0x00007fff9a8dd5af _BlockUntilNextEventMatchingListInModeWithFilter + 71
20  AppKit                              0x00007fff8d7ee0ee _DPSNextEvent + 1067
21  AppKit                              0x00007fff8dbba943 -[NSApplication _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 454
22  DVTKit                              0x00000001097840c2 -[DVTApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 247
23  AppKit                              0x00007fff8d7e3fc8 -[NSApplication run] + 682
24  AppKit                              0x00007fff8d766520 NSApplicationMain + 1176
25  libdyld.dylib                       0x00007fff882df5ad start + 1

Answer 1

Xcode is trying to parse the repository's log entries, and there is a problem with a date.

__NSCFCalendar components:fromDate:]: date cannot be nil

The first thing you need to determine is if this is specific to a single repository. If so, something within the repository is invalid. You could try running git fsck to see if it identifies any corrupt or missing objects.

• Depending on the problem, you may be able to repair, restore, or recover the object.
• At worst, you may have to sacrifice all or some of your history, by initializing a new repository, or by reverting to an earlier backup of the repository then committing your latest changes.

If the problem affects all repositories, determine if the issue is specific to your system. Clone a repository onto a different system and see if their Xcode can show the history.

• If the problem is specific to your system, this could be anything from a problem with an installed package or third-party tools (which affects your repositories), or a corrupt property list (which affects Xcode or its tools). In order of severity, you can try:
  • Deleting and reinstalling Xcode.
  • Deleting directories in ~/Library/Developer/Xcode specifically related to Xcode's user data.
  • Performing a clean installation of the OS, restoring your repositories, then checking that Xcode doesn't crash, during each step of customizing your account and reinstalling other applications and tools.

At worst, this likely isn't a problem with Xcode, making it difficult for anyone else to have a specific answer as to the cause. But by systematically taking steps to identify and fix the issue, you should be able to get back to a state where you can view your source control history.