Backtrace when breakpointing a setter under LLDB

gistfile1.txt

(lldb) thread backtrace
* thread #1: tid = 0x1f03, 0x00001a50 Bugspray`start, stop reason = breakpoint 1.1
    frame #0: 0x00001a50 Bugspray`start
    frame #1: 0x06835d90
    frame #2: 0x00002881 Bugspray`-[BNRViewController calcOperate:] + 113 at BNRViewController.m:78
    frame #3: 0x013bcec9 CoreFoundation`-[NSObject performSelector:withObject:withObject:] + 73
    frame #4: 0x000155c2 UIKit`-[UIApplication sendAction:to:from:forEvent:] + 96
    frame #5: 0x0001555a UIKit`-[UIApplication sendAction:toTarget:fromSender:forEvent:] + 61
    frame #6: 0x000bab76 UIKit`-[UIControl sendAction:to:forEvent:] + 66
    frame #7: 0x000bb03f UIKit`-[UIControl(Internal) _sendActionsForEvents:withEvent:] + 503
    frame #8: 0x000ba2fe UIKit`-[UIControl touchesEnded:withEvent:] + 549
    frame #9: 0x0003aa30 UIKit`-[UIWindow _sendTouchesForEvent:] + 513
    frame #10: 0x0003ac56 UIKit`-[UIWindow sendEvent:] + 273
    frame #11: 0x00021384 UIKit`-[UIApplication sendEvent:] + 464
    frame #12: 0x00014aa9 UIKit`_UIApplicationHandleEvent + 8196
    frame #13: 0x012a5fa9 GraphicsServices`PurpleEventCallback + 1274
    frame #14: 0x0138f1c5 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53
    frame #15: 0x012f4022 CoreFoundation`__CFRunLoopDoSource1 + 146
    frame #16: 0x012f290a CoreFoundation`__CFRunLoopRun + 2218
    frame #17: 0x012f1db4 CoreFoundation`CFRunLoopRunSpecific + 212
    frame #18: 0x012f1ccb CoreFoundation`CFRunLoopRunInMode + 123
    frame #19: 0x012a4879 GraphicsServices`GSEventRunModal + 207
    frame #20: 0x012a493e GraphicsServices`GSEventRun + 114
    frame #21: 0x00012a9b UIKit`UIApplicationMain + 1175
    frame #22: 0x00001b28 Bugspray`main + 152 at main.m:16
    frame #23: 0x00001a85 Bugspray`start + 53