Xcode 6 Crash

[clayallsopp]

The initial & diff popover showed up, but when I clicked to a second diff it crashed. Only happened once, sorry I can't be more helpful =\

Application Specific Information:
ProductBuildVersion: 6A313
UNCAUGHT EXCEPTION (NSInternalInconsistencyException): Invalid parameter not satisfying: aString != nil
UserInfo: (null)
Hints: None
Backtrace:
  0  0x00007fff960a0244 __exceptionPreprocess (in CoreFoundation)
  1  0x000000010224f184 DVTFailureHintExceptionPreprocessor (in DVTFoundation)
  2  0x00007fff921fbe75 objc_exception_throw (in libobjc.A.dylib)
  3  0x00007fff960a0038 +[NSException raise:format:arguments:] (in CoreFoundation)
  4  0x00007fff9636cd41 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] (in Foundation)
  5  0x00007fff8fbe78b8 -[NSCell _objectValue:forString:errorDescription:] (in AppKit)
  6  0x00007fff8fbe780a -[NSCell _objectValue:forString:] (in AppKit)
  7  0x00007fff8fbe7778 -[NSCell setStringValue:] (in AppKit)
  8  0x00007fff8fc63594 -[NSControl setStringValue:] (in AppKit)
  9  0x000000010e49038a -[ORPopoverController tableViewSelectionDidChange:] at /Users/callsopp/Library/Application Support/Alcatraz/Plug-ins/Snapshots/SnapshotDiffs/ORPopoverController.m:83 (in Snapshots)
 10  0x00007fff9606ee0c __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ (in CoreFoundation)
 11  0x00007fff95f6282d _CFXNotificationPost (in CoreFoundation)
 12  0x00007fff962777ba -[NSNotificationCenter postNotificationName:object:userInfo:] (in Foundation)
 13  0x000000010222fe6e -[NSNotificationCenter(DVTNSNotificationCenterAdditions) _dvt_postNotificationName:object:userInfo:] (in DVTFoundation)
 14  0x00007fff8fce7abf -[NSTableView _sendSelectionChangedNotificationForRows:columns:] (in AppKit)
 15  0x00007fff8fc14354 -[NSTableView _enableSelectionPostingAndPost] (in AppKit)
 16  0x00007fff8fdc33dc -[NSTableView mouseDown:] (in AppKit)
 17  0x00007fff8fda8aea forwardMethod (in AppKit)
 18  0x00007fff8fda8aea forwardMethod (in AppKit)
 19  0x00007fff8fda8aea forwardMethod (in AppKit)
 20  0x00007fff8fe2b2b3 -[NSControl mouseDown:] (in AppKit)
 21  0x00007fff8fdaca58 -[NSWindow sendEvent:] (in AppKit)
 22  0x00007fff8fd4b5d4 -[NSApplication sendEvent:] (in AppKit)
 23  0x000000010325ac74 -[IDEApplication sendEvent:] (in IDEKit)
 24  0x00007fff8fb9b9f9 -[NSApplication run] (in AppKit)
 25  0x00007fff8fb86783 NSApplicationMain (in AppKit)
 26  0x00007fff8e8d95fd start (in libdyld.dylib)
 27  0x0000000000000001