I get this crash every time my FinderSync extension starts up:
Process: My Finder Sync [8364]
Path: /Applications/Company/Container.app/Contents/PlugIns/My Finder Sync.appex/Contents/MacOS/My Finder Sync
Identifier: com.company.Container.My-Finder-Sync
Version: [Set on build machine] ([Set on build machine])
Code Type: X86-64 (Native)
Parent Process: ??? [1]
Responsible: My Finder Sync [8364]
User ID: 1129915948
Date/Time: 2019-01-04 11:31:34.146 -0500
OS Version: Mac OS X 10.13.6 (17G4015)
Report Version: 12
Anonymous UUID: 013E2942-CED9-22FA-438A-E3D0BA89EB5C
Sleep/Wake UUID: D21EDE9D-237A-412A-8456-B96453886BAD
Time Awake Since Boot: 3200 seconds
Time Since Wake: 2600 seconds
System Integrity Protection: disabled
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Application Specific Information:
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSDictionaryM setObject:forKey:]: object cannot be nil (key: 37990439-1DFE-4F0B-9865-6FC1D34A3BE4)'
terminating with uncaught exception of type NSException
abort() called
Application Specific Backtrace 1:
0 CoreFoundation 0x00007fff31eb523b __exceptionPreprocess + 171
1 libobjc.A.dylib 0x00007fff59147c76 objc_exception_throw + 48
2 CoreFoundation 0x00007fff31ef64c4 _CFThrowFormattedException + 202
3 CoreFoundation 0x00007fff31db87cc -[__NSDictionaryM setObject:forKey:] + 1020
4 Foundation 0x00007fff3408b348 -[_NSExtensionContextVendor _setPrincipalObject:forUUID:] + 106
5 Foundation 0x00007fff3408ab04 __105-[_NSExtensionContextVendor _beginRequestWithExtensionItems:listenerEndpoint:withContextUUID:completion:]_block_invoke + 804
6 libdispatch.dylib 0x00007fff59d2f5fa _dispatch_call_block_and_release + 12
7 libdispatch.dylib 0x00007fff59d27db8 _dispatch_client_callout + 8
8 libdispatch.dylib 0x00007fff59d33395 _dispatch_main_queue_callback_4CF + 1148
9 CoreFoundation 0x00007fff31e6db39 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
10 CoreFoundation 0x00007fff31e2fcda __CFRunLoopRun + 2586
11 CoreFoundation 0x00007fff31e2f033 CFRunLoopRunSpecific + 483
12 HIToolbox 0x00007fff31119d96 RunCurrentEventLoopInMode + 286
13 HIToolbox 0x00007fff31119b06 ReceiveNextEventCommon + 613
14 HIToolbox 0x00007fff31119884 _BlockUntilNextEventMatchingListInModeWithFilter + 64
15 AppKit 0x00007fff2f3c9a73 _DPSNextEvent + 2085
16 AppKit 0x00007fff2fb5fe34 -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 3044
17 AppKit 0x00007fff2f3be885 -[NSApplication run] + 764
18 AppKit 0x00007fff2f38da72 NSApplicationMain + 804
19 libxpc.dylib 0x00007fff5a0bbd77 _xpc_objc_main + 580
20 libxpc.dylib 0x00007fff5a0ba9ca xpc_main + 433
21 Foundation 0x00007fff33f825f5 +[NSXPCListener serviceListener] + 0
22 PlugInKit 0x00007fff50ddbf8d -[PKService run] + 704
23 PlugInKit 0x00007fff50ddbb99 +[PKService main] + 55
24 PlugInKit 0x00007fff50ddbfb1 +[PKService _defaultRun:arguments:] + 17
25 Foundation 0x00007fff34130229 NSExtensionMain + 51
26 libdyld.dylib 0x00007fff59d61015 start + 1
27 ??? 0x0000000000000001 0x0 + 1
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 libsystem_kernel.dylib 0x00007fff59eb1b66 __pthread_kill + 10
1 libsystem_pthread.dylib 0x00007fff5a07c080 pthread_kill + 333
2 libsystem_c.dylib 0x00007fff59e0d1ae abort + 127
3 libc++abi.dylib 0x00007fff57d07f8f abort_message + 245
4 libc++abi.dylib 0x00007fff57d0812b default_terminate_handler() + 265
5 libobjc.A.dylib 0x00007fff59149ea3 _objc_terminate() + 97
6 libc++abi.dylib 0x00007fff57d237c9 std::__terminate(void (*)()) + 8
7 libc++abi.dylib 0x00007fff57d23843 std::terminate() + 51
8 libdispatch.dylib 0x00007fff59d27dcc _dispatch_client_callout + 28
9 libdispatch.dylib 0x00007fff59d33395 _dispatch_main_queue_callback_4CF + 1148
10 com.apple.CoreFoundation 0x00007fff31e6db39 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
11 com.apple.CoreFoundation 0x00007fff31e2fcda __CFRunLoopRun + 2586
12 com.apple.CoreFoundation 0x00007fff31e2f033 CFRunLoopRunSpecific + 483
13 com.apple.HIToolbox 0x00007fff31119d96 RunCurrentEventLoopInMode + 286
14 com.apple.HIToolbox 0x00007fff31119b06 ReceiveNextEventCommon + 613
15 com.apple.HIToolbox 0x00007fff31119884 _BlockUntilNextEventMatchingListInModeWithFilter + 64
16 com.apple.AppKit 0x00007fff2f3c9a73 _DPSNextEvent + 2085
17 com.apple.AppKit 0x00007fff2fb5fe34 -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 3044
18 com.apple.AppKit 0x00007fff2f3be885 -[NSApplication run] + 764
19 com.apple.AppKit 0x00007fff2f38da72 NSApplicationMain + 804
20 libxpc.dylib 0x00007fff5a0bbd77 _xpc_objc_main + 580
21 libxpc.dylib 0x00007fff5a0ba9ca xpc_main + 433
22 com.apple.Foundation 0x00007fff33f825f5 -[NSXPCListener resume] + 165
23 com.apple.pluginkit.framework 0x00007fff50ddbf8d -[PKService run] + 704
24 com.apple.pluginkit.framework 0x00007fff50ddbb99 +[PKService main] + 55
25 com.apple.pluginkit.framework 0x00007fff50ddbfb1 +[PKService _defaultRun:arguments:] + 17
26 com.apple.Foundation 0x00007fff34130229 NSExtensionMain + 51
27 libdyld.dylib 0x00007fff59d61015 start + 1
Thread 1:
0 libsystem_kernel.dylib 0x00007fff59eb228a __workq_kernreturn + 10
1 libsystem_pthread.dylib 0x00007fff5a079009 _pthread_wqthread + 1035
2 libsystem_pthread.dylib 0x00007fff5a078be9 start_wqthread + 13
Thread 2:
0 libsystem_kernel.dylib 0x00007fff59eb228a __workq_kernreturn + 10
1 libsystem_pthread.dylib 0x00007fff5a079009 _pthread_wqthread + 1035
2 libsystem_pthread.dylib 0x00007fff5a078be9 start_wqthread + 13
Thread 3:
0 libsystem_kernel.dylib 0x00007fff59eb228a __workq_kernreturn + 10
1 libsystem_pthread.dylib 0x00007fff5a079009 _pthread_wqthread + 1035
2 libsystem_pthread.dylib 0x00007fff5a078be9 start_wqthread + 13
Thread 4:
0 libsystem_pthread.dylib 0x00007fff5a078bdc start_wqthread + 0
1 ??? 0x0004000200000006 0 + 1125908496777222
Thread 5:: com.apple.NSEventThread
0 libsystem_kernel.dylib 0x00007fff59ea820a mach_msg_trap + 10
1 libsystem_kernel.dylib 0x00007fff59ea7724 mach_msg + 60
2 com.apple.CoreFoundation 0x00007fff31e30665 __CFRunLoopServiceMachPort + 341
3 com.apple.CoreFoundation 0x00007fff31e2f9b7 __CFRunLoopRun + 1783
4 com.apple.CoreFoundation 0x00007fff31e2f033 CFRunLoopRunSpecific + 483
5 com.apple.AppKit 0x00007fff2f506fc4 _NSEventThread + 184
6 libsystem_pthread.dylib 0x00007fff5a079661 _pthread_body + 340
7 libsystem_pthread.dylib 0x00007fff5a07950d _pthread_start + 377
8 libsystem_pthread.dylib 0x00007fff5a078bf9 thread_start + 13
Thread 0 crashed with X86 Thread State (64-bit):
rax: 0x0000000000000000 rbx: 0x00007fff927a7380 rcx: 0x00007ffee31a6c68 rdx: 0x0000000000000000
rdi: 0x0000000000000307 rsi: 0x0000000000000006 rbp: 0x00007ffee31a6ca0 rsp: 0x00007ffee31a6c68
r8: 0x00007ffee31a6b30 r9: 0x00007ffee31a6d00 r10: 0x0000000000000000 r11: 0x0000000000000206
r12: 0x0000000000000307 r13: 0x0000000000000030 r14: 0x0000000000000006 r15: 0x000000000000002d
rip: 0x00007fff59eb1b66 rfl: 0x0000000000000206 cr2: 0x00007fff92784168
As you can see there's only Apple platform stuff in there. Even worse, is that this happens before any of my code is called! At least, it never hits my breakpoint in my FIFinderSync class' init.
So what's going on here? Why is it crashing with something about a UUID key and nil value in some dictionary? I've gone through all my code and ensured that can't happen (I do have some dictionaries like that, but all are in Swift code and the values are not optional so can never be nil; nevermind that their breakpoints aren't hit either).
Swift does some name mangling, even when it doesn't seem like it. When you do something like reference a class name via a string, like in a FinderSync extension's info.plist, that doesn't always work as intended in Swift.
For instance, if you have a class like:
@objc
class MyFinderSyncPrinicpalClass: FIFinderSync {
// ...
}
try compiling that and looking at the generated Obj-C header. It probably looks something like this:
SWIFT_CLASS("_TtC17My_Finder_Sync10MyFinderSyncPrinicpalClass")
@interface MyFinderSyncPrinicpalClass : FIFinderSync
// ...
@end
This means that Swift and Objective-C code can both simply refer to it as MyFinderSyncPrinicpalClass, but anything that wants to refer to its compiled form via a string, such as in reflection or that info.plist, sees that mangled name _TtC17My_Finder_Sync10MyFinderSyncPrinicpalClass. To fix this, simply specify the name explicitly in the @objc annotation:
@objc(MyFinderSyncPrinicpalClass)
class MyFinderSyncPrinicpalClass: FIFinderSync {
// ...
}
Now if you compare that to the newly-generated Obj-C header, you'll see what I mean:
SWIFT_CLASS("MyFinderSyncPrinicpalClass")
@interface MyFinderSyncPrinicpalClass : FIFinderSync
// ...
@end
Now you may refer to it by its actual name in info.plist, and it'll be started up as intended!