我正在学习如何分析崩溃报告。我故意在我的swift应用程序代码中添加错误并查看生成的崩溃报告。当错误出现在后台异步线程中运行的代码块中时，崩溃报告不会识别崩溃的代码行号。
是否可以从崩溃中获取此行号？
以下是崩溃报告的一部分：
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000001, 0x00000001020791fc
Triggered by Thread: 5
Filtered syslog:
None found
Global Trace Buffer (reverse chronological seconds):
2.965970 AppleJPEG 0x000000018300e26c [0x13e05f000] Created session
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0:
0 QuartzCore 0x00000001840921f4 slab_alloc + 392
1 QuartzCore 0x0000000184092058 magazine_alloc_ + 304
2 QuartzCore 0x0000000184092058 magazine_alloc_ + 304
3 QuartzCore 0x000000018408eee8 x_mem_alloc_bucket + 144
4 QuartzCore 0x000000018408eb94 CA::AttrList::set(unsigned int, _CAValueType, void const*) + 160
5 QuartzCore 0x0000000184092398 CA::Layer::setter(unsigned int, _CAValueType, void const*) + 208
6 QuartzCore 0x0000000184099ec4 -[CALayer setOpacity:] + 48
7 UIKit 0x00000001869a7678 __53-[_UINavigationParallaxTransition animateTransition:]_block_invoke_2 + 1072
8 UIKit 0x000000018671b5b4 +[UIView(Animation) performWithoutAnimation:] + 80
9 UIKit 0x00000001869068d4 __53-[_UINavigationParallaxTransition animateTransition:]_block_invoke + 260
10 UIKit 0x0000000186a26334 +[UIView(Internal) _performBlockDelayingTriggeringResponderEvents:] + 220
11 UIKit 0x000000018690644c -[_UINavigationParallaxTransition animateTransition:] + 1060
12 UIKit 0x00000001868c0818 -[UINavigationController _startCustomTransition:] + 3544
13 UIKit 0x00000001867cbe40 -[UINavigationController _startDeferredTransitionIfNeeded:] + 688
14 UIKit 0x00000001867cbb1c -[UINavigationController __viewWillLayoutSubviews] + 60
15 UIKit 0x00000001867cba84 -[UILayoutContainerView layoutSubviews] + 208
16 UIKit 0x00000001867081e4 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 656
17 QuartzCore 0x000000018409a994 -[CALayer layoutSublayers] + 148
18 QuartzCore 0x00000001840955d0 CA::Layer::layout_if_needed(CA::Transaction*) + 292
19 QuartzCore 0x0000000184095490 CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 32
20 QuartzCore 0x0000000184094ac0 CA::Context::commit_transaction(CA::Transaction*) + 252
21 QuartzCore 0x0000000184094820 CA::Transaction::commit() + 500
22 QuartzCore 0x000000018408dde4 CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) + 80
23 CoreFoundation 0x0000000181564728 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 32
24 CoreFoundation 0x00000001815624cc __CFRunLoopDoObservers + 372
25 CoreFoundation 0x00000001815628fc __CFRunLoopRun + 928
26 CoreFoundation 0x000000018148cc50 CFRunLoopRunSpecific + 384
27 GraphicsServices 0x0000000182d74088 GSEventRunModal + 180
28 UIKit 0x0000000186776088 UIApplicationMain + 204
29 MargRiver 0x00000001000fc378 main (AppDelegate.swift:27)
30 libdyld.dylib 0x000000018102a8b8 start + 4
Thread 1 name: Dispatch queue: com.apple.libdispatch-manager
Thread 1:
0 libsystem_kernel.dylib 0x00000001811494d8 kevent_qos + 8
1 libdispatch.dylib 0x000000018100c7d8 _dispatch_mgr_invoke + 232
2 libdispatch.dylib 0x0000000180ffb648 _dispatch_source_invoke + 0
Thread 2:
0 libsystem_kernel.dylib 0x0000000181148b48 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x0000000181211530 _pthread_wqthread + 1284
2 libsystem_pthread.dylib 0x0000000181211020 start_wqthread + 4
Thread 3:
0 libsystem_kernel.dylib 0x0000000181148b48 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x0000000181211530 _pthread_wqthread + 1284
2 libsystem_pthread.dylib 0x0000000181211020 start_wqthread + 4
Thread 4:
0 libsystem_kernel.dylib 0x0000000181148b48 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x0000000181211530 _pthread_wqthread + 1284
2 libsystem_pthread.dylib 0x0000000181211020 start_wqthread + 4
Thread 5 name: Dispatch queue: com.apple.root.background-qos
Thread 5 Crashed:
0 libswiftCore.dylib 0x00000001020791fc 0x101f38000 + 1315324
1 libswiftCore.dylib 0x00000001020791fc 0x101f38000 + 1315324
2 MargRiver 0x00000001000ea908 EntriesListController.(loadEntries(completion : () -> ()?) -> ()).(closure #1) (EntriesListController.swift:0)
3 MargRiver 0x00000001000ae798 thunk (MoreViewController.swift:0)
4 libdispatch.dylib 0x0000000180ff94bc _dispatch_call_block_and_release + 24
5 libdispatch.dylib 0x0000000180ff947c _dispatch_client_callout + 16
6 libdispatch.dylib 0x0000000181007914 _dispatch_root_queue_drain + 2140
7 libdispatch.dylib 0x00000001810070b0 _dispatch_worker_thread3 + 112
8 libsystem_pthread.dylib 0x0000000181211470 _pthread_wqthread + 1092
9 libsystem_pthread.dylib 0x0000000181211020 start_wqthread + 4
Thread 5 crashed with ARM Thread State (64-bit):
x0: 0x00000001028d1400 x1: 0x000000018120a8f4 x2: 0x000000013d512300 x3: 0x0000000000000008
x4: 0x0000000000000000 x5: 0x0000000000000010 x6: 0x0000000000000000 x7: 0x0000000000000fa0
x8: 0x00000001028d1408 x9: 0x0000000000001000 x10: 0x000000013d514000 x11: 0x0000000000000fff
x12: 0x000000013d510000 x13: 0x0000000000003fff x14: 0xffffffffffffc000 x15: 0x0000000000003fff
x16: 0x0000000181174168 x17: 0x000000010215c048 x18: 0x0000000000000000 x19: 0x0000000000000000
x20: 0x0000000000000002 x21: 0x0000000000000039 x22: 0x0000000100727500 x23: 0x0000000000000002
x24: 0x000000000000000b x25: 0x000000010072753a x26: 0x000000016e2470e0 x27: 0x000000016e2470e0
x28: 0x0000000000000000 fp: 0x000000016e246720 lr: 0x00000001020791fc
sp: 0x000000016e2466e0 pc: 0x00000001020791fc cpsr: 0x20000000
这是loadEntries（）函数的开头：
fileprivate func loadEntries(completion: (() -> Void)?) -> Void {
let timeStartDb = Date()
var timeEndDb: Date!
var sqlStatement: String!
var newEntries = [Entry]()
var newSelectedSegment = false // true => the selected segment control button is different from last time loadEntries() was called
DispatchQueue.global(qos: .background).async {
if (self.listOrderSegControl.selectedSegmentIndex != self.previousSelectedSegmentIndex) {
newSelectedSegment = true
self.previousSelectedSegmentIndex = self.listOrderSegControl.selectedSegmentIndex
}
switch (self.listOrderSegControl.selectedSegmentIndex) {
case EntriesListController.LIST_ORDER_DISTANCE:
sqlStatement = self.sqlSubStatement + self.distanceSortOrder
case EntriesListController.LIST_ORDER_AZ:
sqlStatement = self.sqlSubStatement + "title"
case EntriesListController.LIST_ORDER_RECOMMENDED:
sqlStatement = self.sqlSubStatement + "prio"
default:
sqlStatement = self.sqlSubStatement + "prio"
self.previousSelectedSegmentIndex = EntriesListController.LIST_ORDER_RECOMMENDED
}
代码在switch语句中崩溃，因为self.sqlSubStatement = nil。正如我上面提到的，我故意添加了这个bug，以便学习如何使用崩溃报告。然而，崩溃报告没有识别出包含该错误的代码行。是否可以识别它？