How to use `thread backtrace -e true` in `lldb`.

terminal.sh-session

$ echo 'import Dispatch; func f() {}; DispatchQueue.global(qos: .default).async { f() }; dispatchMain()'|swiftc -
$ lldb
(lldb) target create main
Current executable set to 'main' (x86_64).
(lldb) b f
Breakpoint 1: 9 locations.
(lldb) process launch -v DYLD_LIBRARY_PATH=/usr/lib/system/introspection -v DYLD_INSERT_LIBRARIES=/Applications/Xcode.app/Contents/Developer/usr/lib/libBacktraceRecording.dylib
Process 33297 launched: '/Users/norio/github/swift-dev/SourceKitten/main' (x86_64)
Process 33297 stopped
* thread #2, queue = 'com.apple.root.default-qos', stop reason = breakpoint 1.1
    frame #0: 0x00000001000017d0 main`main.f() -> ()
main`main.f() -> ():
->  0x1000017d0 <+0>: pushq  %rbp
    0x1000017d1 <+1>: movq   %rsp, %rbp
    0x1000017d4 <+4>: popq   %rbp
    0x1000017d5 <+5>: retq   
Target 0: (main) stopped.
(lldb) thread backtrace -e true
* thread #2, queue = 'com.apple.root.default-qos', stop reason = breakpoint 1.1
  * frame #0: 0x00000001000017d0 main`main.f() -> ()
    frame #1: 0x00000001000017e9 main`closure #1 () -> () in main + 9
    frame #2: 0x000000010000181d main`reabstraction thunk helper from @escaping @callee_guaranteed () -> () to @escaping @callee_unowned @convention(block) () -> () + 45
    frame #3: 0x000000010079dcae libdispatch.dylib`_dispatch_call_block_and_release + 12
    frame #4: 0x0000000100795d8f libdispatch.dylib`_dispatch_client_callout + 8
    frame #5: 0x00000001007a3c14 libdispatch.dylib`_dispatch_queue_override_invoke + 1387
    frame #6: 0x0000000100797bea libdispatch.dylib`_dispatch_root_queue_drain + 723
    frame #7: 0x00000001007978c3 libdispatch.dylib`_dispatch_worker_thread3 + 116
    frame #8: 0x000000010081216d libsystem_pthread.dylib`_pthread_wqthread + 1387
    frame #9: 0x0000000100811bed libsystem_pthread.dylib`start_wqthread + 13
  thread #4294967295: tid = 0x23f8f3, 0x00000001007ac678 libdispatch.dylib`_dispatch_root_queue_push_override + 325, queue = 'com.apple.main-thread'
    frame #0: 0x00000001007ac678 libdispatch.dylib`_dispatch_root_queue_push_override + 325
    frame #1: 0x000000010073d69e libswiftDispatch.dylib`(extension in Dispatch):__C.OS_dispatch_queue.async(group: Swift.Optional<__C.OS_dispatch_group>, qos: Dispatch.DispatchQoS, flags: Dispatch.DispatchWorkItemFlags, execute: @convention(block) () -> ()) -> () + 318
    frame #2: 0x000000010000174b main`main + 187
    frame #3: 0x00007fff5555d015 libdyld.dylib`start + 1
(lldb)