reproduce step.
push native -> push Flutter Page -> Open second route -> push native -> push Flutter Page -> Open second route -> push native -> back -> back-> back-> back-> back ..... crash
bt all
thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=EXC_I386_GPFLT)
frame #0: 0x00007fff5086078b libobjc.A.dylib`objc_msgSend + 11
frame #1: 0x0000000100c3a7ba Flutter`flutter::AccessibilityBridge::~AccessibilityBridge() + 64
frame #2: 0x0000000100c41a25 Flutter`std::__1::unique_ptr<flutter::AccessibilityBridge, std::__1::default_delete<flutter::AccessibilityBridge> >::reset(flutter::AccessibilityBridge*) + 25
frame #3: 0x0000000100c41822 Flutter`flutter::PlatformViewIOS::SetOwnerViewController(fml::WeakPtr<FlutterViewController>) + 82
frame #4: 0x0000000100c22add Flutter`-[FlutterEngine setViewController:] + 167
* frame #5: 0x00000001008e6da5 Runner`-[FLBFlutterEngine detach](self=0x0000600001ae11e0, _cmd="detach") at FLBFlutterEngine.m:120:17
frame #6: 0x00000001008e7cf3 Runner`-[FLBFlutterViewContainer detatchFlutterEngine](self=0x00007fa4298c6200, _cmd="detatchFlutterEngine") at FLBFlutterViewContainer.m:146:5
frame #7: 0x00000001008e7edc Runner`-[FLBFlutterViewContainer viewWillAppear:](self=0x00007fa4298c6200, _cmd="viewWillAppear:", animated=YES) at FLBFlutterViewContainer.m:166:9
frame #8: 0x00007fff46f0ebd5 UIKitCore`-[UIViewController _setViewAppearState:isAnimating:] + 661
frame #9: 0x00007fff46f0f2f1 UIKitCore`-[UIViewController __viewWillAppear:] + 115
frame #10: 0x00007fff46e59081 UIKitCore`-[UINavigationController _startCustomTransition:] + 1247
frame #11: 0x00007fff46e6e3d0 UIKitCore`-[UINavigationController _startDeferredTransitionIfNeeded:] + 698
frame #12: 0x00007fff46e6f7e5 UIKitCore`-[UINavigationController __viewWillLayoutSubviews] + 150
frame #13: 0x00007fff46e51127 UIKitCore`-[UILayoutContainerView layoutSubviews] + 217
frame #14: 0x00007fff47a52ad5 UIKitCore`-[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 2478
frame #15: 0x00007fff2b06e91d QuartzCore`-[CALayer layoutSublayers] + 255
frame #16: 0x00007fff2b073323 QuartzCore`CA::Layer::layout_if_needed(CA::Transaction*) + 517
frame #17: 0x00007fff2b07fa7c QuartzCore`CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 80
frame #18: 0x00007fff2afc6e54 QuartzCore`CA::Context::commit_transaction(CA::Transaction*, double) + 324
frame #19: 0x00007fff2affc32f QuartzCore`CA::Transaction::commit() + 643
frame #20: 0x00007fff475723b4 UIKitCore`_UIApplicationFlushRunLoopCATransactionIfTooLate + 104
frame #21: 0x00007fff47614cba UIKitCore`__handleEventQueueInternal + 6902
frame #22: 0x00007fff23b0d271 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
frame #23: 0x00007fff23b0d19c CoreFoundation`__CFRunLoopDoSource0 + 76
frame #24: 0x00007fff23b0c974 CoreFoundation`__CFRunLoopDoSources0 + 180
frame #25: 0x00007fff23b0767f CoreFoundation`__CFRunLoopRun + 1263
frame #26: 0x00007fff23b06e66 CoreFoundation`CFRunLoopRunSpecific + 438
frame #27: 0x00007fff38346bb0 GraphicsServices`GSEventRunModal + 65
frame #28: 0x00007fff47578dd0 UIKitCore`UIApplicationMain + 1621
frame #29: 0x00000001008e0370 Runner`main(argc=1, argv=0x00007ffeef31fd48) at main.m:7:12
frame #30: 0x00007fff516ecd29 libdyld.dylib`start + 1
frame #31: 0x00007fff516ecd29 libdyld.dylib`start + 1
thread #5
frame #0: 0x00007fff51824b9a libsystem_kernel.dylib`__workq_kernreturn + 10
frame #1: 0x00007fff518d177f libsystem_pthread.dylib`_pthread_wqthread + 390
frame #2: 0x00007fff518d157b libsystem_pthread.dylib`start_wqthread + 15
thread #6, name = 'com.apple.uikit.eventfetch-thread'
frame #0: 0x00007fff51823166 libsystem_kernel.dylib`mach_msg_trap + 10
frame #1: 0x00007fff518236cc libsystem_kernel.dylib`mach_msg + 60
frame #2: 0x00007fff23b0caf5 CoreFoundation`__CFRunLoopServiceMachPort + 197
frame #3: 0x00007fff23b07817 CoreFoundation`__CFRunLoopRun + 1671
frame #4: 0x00007fff23b06e66 CoreFoundation`CFRunLoopRunSpecific + 438
frame #5: 0x00007fff2569694f Foundation`-[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 211
frame #6: 0x00007fff25696bc2 Foundation`-[NSRunLoop(NSRunLoop) runUntilDate:] + 72
frame #7: 0x00007fff4761a768 UIKitCore`-[UIEventFetcher threadMain] + 138
frame #8: 0x00007fff256ac887 Foundation`__NSThread__start__ + 1047
frame #9: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #8
frame #0: 0x00007fff51824b9a libsystem_kernel.dylib`__workq_kernreturn + 10
frame #1: 0x00007fff518d177f libsystem_pthread.dylib`_pthread_wqthread + 390
frame #2: 0x00007fff518d157b libsystem_pthread.dylib`start_wqthread + 15
thread #9, name = 'io.flutter.2.ui'
frame #0: 0x00000001118a8588
frame #1: 0x0000000111468fb6
frame #2: 0x0000000111468c2f
frame #3: 0x0000000110e03622
frame #4: 0x00000001112fb182
frame #5: 0x00000001112fa042
frame #6: 0x00000001112f9860
frame #7: 0x0000000111a4ac3a
frame #8: 0x000000011220a8f2
frame #9: 0x000000010cd47112
frame #10: 0x0000000112208d07
frame #11: 0x000000010cd48b64
frame #12: 0x000000010cd42625
frame #13: 0x00000001122090c6
frame #14: 0x000000010cd48b64
frame #15: 0x000000010cd42625
frame #16: 0x00000001122090c6
frame #17: 0x000000010cd48b64
frame #18: 0x0000000111467265
frame #19: 0x0000000112209108
frame #20: 0x000000010cd48b64
frame #21: 0x0000000111467265
frame #22: 0x00000001122090e7
frame #23: 0x000000010cd48b64
frame #24: 0x000000010cd42625
frame #25: 0x00000001122090c6
frame #26: 0x000000010cd48b64
frame #27: 0x0000000111467265
frame #28: 0x00000001122090e7
frame #29: 0x000000010cd48b64
frame #30: 0x0000000111467265
frame #31: 0x00000001122090e7
frame #32: 0x000000010cd48b64
frame #33: 0x000000010cd42ffe
frame #34: 0x000000011220919c
frame #35: 0x000000010cd48b64
frame #36: 0x0000000111467265
frame #37: 0x0000000112209108
frame #38: 0x000000010cd48b64
frame #39: 0x0000000111467265
frame #40: 0x00000001122090e7
frame #41: 0x000000010cd48b64
frame #42: 0x0000000111467265
frame #43: 0x0000000112209108
frame #44: 0x000000010cd48b64
frame #45: 0x000000010cd42625
frame #46: 0x00000001122090c6
frame #47: 0x000000010cd48b64
frame #48: 0x0000000111467265
frame #49: 0x00000001122090e7
frame #50: 0x000000010cd48b64
frame #51: 0x000000010cd42625
frame #52: 0x00000001122090c6
frame #53: 0x000000010cd48b64
frame #54: 0x0000000111467265
frame #55: 0x0000000112209108
frame #56: 0x000000010cd48b64
frame #57: 0x0000000111467265
frame #58: 0x0000000112209108
frame #59: 0x000000010cd48b64
frame #60: 0x0000000111467265
frame #61: 0x00000001122090e7
frame #62: 0x000000010cd48b64
frame #63: 0x0000000111467265
frame #64: 0x00000001122090e7
frame #65: 0x000000010cd48b64
frame #66: 0x0000000111467265
frame #67: 0x0000000112209108
frame #68: 0x000000010cd48b64
frame #69: 0x0000000111467265
frame #70: 0x00000001122090e7
frame #71: 0x000000010cd48b64
frame #72: 0x000000010cd42625
frame #73: 0x00000001122090c6
frame #74: 0x000000010cd48b64
frame #75: 0x0000000111467265
frame #76: 0x00000001122090e7
frame #77: 0x000000010cd48b64
frame #78: 0x000000010cd42625
frame #79: 0x00000001122090c6
frame #80: 0x000000010cd48b64
frame #81: 0x000000010cd42625
frame #82: 0x00000001122090c6
frame #83: 0x000000010cd48b64
frame #84: 0x0000000111467265
frame #85: 0x0000000112209108
frame #86: 0x000000010cd48b64
frame #87: 0x000000010cd42625
frame #88: 0x00000001122090c6
frame #89: 0x000000010cd48b64
frame #90: 0x0000000111467265
frame #91: 0x0000000112209165
frame #92: 0x000000010cd48b64
frame #93: 0x000000010cd42625
frame #94: 0x00000001122090c6
frame #95: 0x000000010cd48b64
frame #96: 0x0000000111467265
frame #97: 0x0000000112209108
frame #98: 0x000000010cd48b64
frame #99: 0x0000000111467265
frame #100: 0x00000001122090e7
frame #101: 0x000000010cd48b64
frame #102: 0x000000010cd42625
frame #103: 0x00000001122090c6
frame #104: 0x000000010cd48b64
frame #105: 0x0000000111467265
frame #106: 0x00000001122090e7
frame #107: 0x000000010cd48b64
frame #108: 0x0000000111467265
frame #109: 0x0000000112209108
frame #110: 0x000000010cd48b64
frame #111: 0x0000000111467265
frame #112: 0x0000000112209108
frame #113: 0x000000010cd48b64
frame #114: 0x000000010cd42ffe
frame #115: 0x000000011220919c
frame #116: 0x000000010cd48b64
frame #117: 0x000000010cd428ed
frame #118: 0x000000011220919c
frame #119: 0x000000010cd48b64
frame #120: 0x0000000111467265
frame #121: 0x0000000112209108
frame #122: 0x000000010cd48b64
frame #123: 0x0000000111467265
frame #124: 0x0000000112209165
frame #125: 0x000000010cd48b64
frame #126: 0x000000010cd42625
frame #127: 0x00000001122090c6
frame #128: 0x000000010cd48b64
frame #129: 0x0000000111467265
frame #130: 0x0000000112209108
frame #131: 0x000000010cd48b64
frame #132: 0x000000010cd42625
frame #133: 0x00000001122090c6
frame #134: 0x000000010cd48b64
frame #135: 0x000000010cd42625
frame #136: 0x00000001122090c6
frame #137: 0x000000010cd48b64
frame #138: 0x0000000111467265
frame #139: 0x00000001122090e7
frame #140: 0x000000010cd48b64
frame #141: 0x0000000111467265
frame #142: 0x0000000112209108
frame #143: 0x000000010cd4665e
frame #144: 0x0000000110bd4fff
frame #145: 0x00000001118bb04b
frame #146: 0x000000011220e33f
frame #147: 0x00000001118b879d
frame #148: 0x0000000110bdf116
frame #149: 0x0000000110bd8f71
frame #150: 0x0000000110bd848f
frame #151: 0x0000000110bd5336
frame #152: 0x00000001118bb04b
frame #153: 0x00000001112cd2d0
frame #154: 0x00000001112ca083
frame #155: 0x00000001118ba92e
frame #156: 0x00000001112c8e28
frame #157: 0x00000001118ba92e
frame #158: 0x000000011220e33f
frame #159: 0x00000001118b879d
frame #160: 0x0000000110bcbac0
frame #161: 0x0000000110ee6174
frame #162: 0x0000000110ee5a96
frame #163: 0x0000000110ee599d
frame #164: 0x0000000110ee5104
frame #165: 0x0000000110ee4442
frame #166: 0x00000001112c805e
frame #167: 0x00000001112c7eb4
frame #168: 0x000000010d123186
frame #169: 0x000000010d122f0c
frame #170: 0x000000010d122482
frame #171: 0x0000000110ed6645
frame #172: 0x000000010d107d09
frame #173: 0x00000001112c7a65
frame #174: 0x00000001032c166c
frame #175: 0x00000001011016ff Flutter`dart::DartEntry::InvokeFunction(dart::Function const&, dart::Array const&, dart::Array const&, unsigned long) + 975
frame #176: 0x00000001011ad135 Flutter`dart::Library::Invoke(dart::String const&, dart::Array const&, dart::Array const&, bool, bool) const + 1029
frame #177: 0x0000000101456868 Flutter`Dart_Invoke + 1592
frame #178: 0x0000000100c7972a Flutter`flutter::Window::BeginFrame(fml::TimePoint) + 270
frame #179: 0x0000000100c832ca Flutter`flutter::RuntimeController::BeginFrame(fml::TimePoint) + 30
frame #180: 0x0000000100c8af83 Flutter`flutter::Engine::BeginFrame(fml::TimePoint) + 53
frame #181: 0x0000000100c87d17 Flutter`flutter::Animator::BeginFrame(fml::TimePoint, fml::TimePoint) + 447
frame #182: 0x0000000100c3f2dd Flutter`std::__1::function<void (fml::TimePoint, fml::TimePoint)>::operator()(fml::TimePoint, fml::TimePoint) const + 39
frame #183: 0x0000000100ca2956 Flutter`std::__1::__function::__func<flutter::VsyncWaiter::FireCallback(fml::TimePoint, fml::TimePoint)::$_0, std::__1::allocator<flutter::VsyncWaiter::FireCallback(fml::TimePoint, fml::TimePoint)::$_0>, void ()>::operator()() + 108
frame #184: 0x0000000100c503f1 Flutter`fml::MessageLoopImpl::FlushTasks(fml::FlushType) + 123
frame #185: 0x0000000100c55742 Flutter`fml::MessageLoopDarwin::OnTimerFire(__CFRunLoopTimer*, fml::MessageLoopDarwin*) + 26
frame #186: 0x00007fff23b0d994 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
frame #187: 0x00007fff23b0d682 CoreFoundation`__CFRunLoopDoTimer + 1026
frame #188: 0x00007fff23b0ccda CoreFoundation`__CFRunLoopDoTimers + 266
frame #189: 0x00007fff23b07a4e CoreFoundation`__CFRunLoopRun + 2238
frame #190: 0x00007fff23b06e66 CoreFoundation`CFRunLoopRunSpecific + 438
frame #191: 0x0000000100c5586d Flutter`fml::MessageLoopDarwin::Run() + 65
frame #192: 0x0000000100c50330 Flutter`fml::MessageLoopImpl::DoRun() + 22
frame #193: 0x0000000100c54d98 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::Thread::Thread(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0> >(void*) + 170
frame #194: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #195: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #10, name = 'io.flutter.1.ui'
frame #0: 0x00007fff51823166 libsystem_kernel.dylib`mach_msg_trap + 10
frame #1: 0x00007fff518236cc libsystem_kernel.dylib`mach_msg + 60
frame #2: 0x00007fff23b0caf5 CoreFoundation`__CFRunLoopServiceMachPort + 197
frame #3: 0x00007fff23b07817 CoreFoundation`__CFRunLoopRun + 1671
frame #4: 0x00007fff23b06e66 CoreFoundation`CFRunLoopRunSpecific + 438
frame #5: 0x0000000100c5586d Flutter`fml::MessageLoopDarwin::Run() + 65
frame #6: 0x0000000100c50330 Flutter`fml::MessageLoopImpl::DoRun() + 22
frame #7: 0x0000000100c54d98 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::Thread::Thread(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0> >(void*) + 170
frame #8: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #9: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #11, name = 'io.flutter.1.gpu'
frame #0: 0x00007fff51823166 libsystem_kernel.dylib`mach_msg_trap + 10
frame #1: 0x00007fff518236cc libsystem_kernel.dylib`mach_msg + 60
frame #2: 0x00007fff23b0caf5 CoreFoundation`__CFRunLoopServiceMachPort + 197
frame #3: 0x00007fff23b07817 CoreFoundation`__CFRunLoopRun + 1671
frame #4: 0x00007fff23b06e66 CoreFoundation`CFRunLoopRunSpecific + 438
frame #5: 0x0000000100c5586d Flutter`fml::MessageLoopDarwin::Run() + 65
frame #6: 0x0000000100c50330 Flutter`fml::MessageLoopImpl::DoRun() + 22
frame #7: 0x0000000100c54d98 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::Thread::Thread(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0> >(void*) + 170
frame #8: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #9: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #12, name = 'io.flutter.1.io'
frame #0: 0x00007fff51823166 libsystem_kernel.dylib`mach_msg_trap + 10
frame #1: 0x00007fff518236cc libsystem_kernel.dylib`mach_msg + 60
frame #2: 0x00007fff23b0caf5 CoreFoundation`__CFRunLoopServiceMachPort + 197
frame #3: 0x00007fff23b07817 CoreFoundation`__CFRunLoopRun + 1671
frame #4: 0x00007fff23b06e66 CoreFoundation`CFRunLoopRunSpecific + 438
frame #5: 0x0000000100c5586d Flutter`fml::MessageLoopDarwin::Run() + 65
frame #6: 0x0000000100c50330 Flutter`fml::MessageLoopImpl::DoRun() + 22
frame #7: 0x0000000100c54d98 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::Thread::Thread(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0> >(void*) + 170
frame #8: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #9: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #13, name = 'io.flutter.worker.1'
frame #0: 0x00007fff51826916 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007fff518d5040 libsystem_pthread.dylib`_pthread_cond_wait + 701
frame #2: 0x00007fff4f68beda libc++.1.dylib`std::__1::condition_variable::wait(std::__1::unique_lock<std::__1::mutex>&) + 18
frame #3: 0x0000000100c4d5bf Flutter`fml::ConcurrentMessageLoop::WorkerMain() + 183
frame #4: 0x0000000100c4db87 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::ConcurrentMessageLoop::ConcurrentMessageLoop(unsigned long)::$_0> >(void*) + 164
frame #5: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #6: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #14, name = 'io.flutter.worker.2'
frame #0: 0x00007fff51826916 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007fff518d5040 libsystem_pthread.dylib`_pthread_cond_wait + 701
frame #2: 0x00007fff4f68beda libc++.1.dylib`std::__1::condition_variable::wait(std::__1::unique_lock<std::__1::mutex>&) + 18
frame #3: 0x0000000100c4d5bf Flutter`fml::ConcurrentMessageLoop::WorkerMain() + 183
frame #4: 0x0000000100c4db87 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::ConcurrentMessageLoop::ConcurrentMessageLoop(unsigned long)::$_0> >(void*) + 164
frame #5: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #6: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #15, name = 'io.flutter.worker.3'
frame #0: 0x00007fff51826916 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007fff518d5040 libsystem_pthread.dylib`_pthread_cond_wait + 701
frame #2: 0x00007fff4f68beda libc++.1.dylib`std::__1::condition_variable::wait(std::__1::unique_lock<std::__1::mutex>&) + 18
frame #3: 0x0000000100c4d5bf Flutter`fml::ConcurrentMessageLoop::WorkerMain() + 183
frame #4: 0x0000000100c4db87 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::ConcurrentMessageLoop::ConcurrentMessageLoop(unsigned long)::$_0> >(void*) + 164
frame #5: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #6: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #16, name = 'io.flutter.worker.4'
frame #0: 0x00007fff51826916 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007fff518d5040 libsystem_pthread.dylib`_pthread_cond_wait + 701
frame #2: 0x00007fff4f68beda libc++.1.dylib`std::__1::condition_variable::wait(std::__1::unique_lock<std::__1::mutex>&) + 18
frame #3: 0x0000000100c4d5bf Flutter`fml::ConcurrentMessageLoop::WorkerMain() + 183
frame #4: 0x0000000100c4db87 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::ConcurrentMessageLoop::ConcurrentMessageLoop(unsigned long)::$_0> >(void*) + 164
frame #5: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #6: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #17, name = 'io.flutter.worker.5'
frame #0: 0x00007fff51826916 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007fff518d5040 libsystem_pthread.dylib`_pthread_cond_wait + 701
frame #2: 0x00007fff4f68beda libc++.1.dylib`std::__1::condition_variable::wait(std::__1::unique_lock<std::__1::mutex>&) + 18
frame #3: 0x0000000100c4d5bf Flutter`fml::ConcurrentMessageLoop::WorkerMain() + 183
frame #4: 0x0000000100c4db87 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::ConcurrentMessageLoop::ConcurrentMessageLoop(unsigned long)::$_0> >(void*) + 164
frame #5: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #6: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #18, name = 'io.flutter.worker.6'
frame #0: 0x00007fff51826916 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007fff518d5040 libsystem_pthread.dylib`_pthread_cond_wait + 701
frame #2: 0x00007fff4f68beda libc++.1.dylib`std::__1::condition_variable::wait(std::__1::unique_lock<std::__1::mutex>&) + 18
frame #3: 0x0000000100c4d5bf Flutter`fml::ConcurrentMessageLoop::WorkerMain() + 183
frame #4: 0x0000000100c4db87 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::ConcurrentMessageLoop::ConcurrentMessageLoop(unsigned long)::$_0> >(void*) + 164
frame #5: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #6: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #19, name = 'io.flutter.worker.7'
frame #0: 0x00007fff51826916 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007fff518d5040 libsystem_pthread.dylib`_pthread_cond_wait + 701
frame #2: 0x00007fff4f68beda libc++.1.dylib`std::__1::condition_variable::wait(std::__1::unique_lock<std::__1::mutex>&) + 18
frame #3: 0x0000000100c4d5bf Flutter`fml::ConcurrentMessageLoop::WorkerMain() + 183
frame #4: 0x0000000100c4db87 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::ConcurrentMessageLoop::ConcurrentMessageLoop(unsigned long)::$_0> >(void*) + 164
frame #5: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #6: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #20, name = 'io.flutter.worker.8'
frame #0: 0x00007fff51826916 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007fff518d5040 libsystem_pthread.dylib`_pthread_cond_wait + 701
frame #2: 0x00007fff4f68beda libc++.1.dylib`std::__1::condition_variable::wait(std::__1::unique_lock<std::__1::mutex>&) + 18
frame #3: 0x0000000100c4d5bf Flutter`fml::ConcurrentMessageLoop::WorkerMain() + 183
frame #4: 0x0000000100c4db87 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::ConcurrentMessageLoop::ConcurrentMessageLoop(unsigned long)::$_0> >(void*) + 164
frame #5: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #6: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #21, name = 'dart:io EventHandler'
frame #0: 0x00007fff5182998a libsystem_kernel.dylib`kevent + 10
frame #1: 0x0000000100fe6068 Flutter`dart::bin::EventHandlerImplementation::EventHandlerEntry(unsigned long) + 264
frame #2: 0x00000001010012ed Flutter`dart::bin::ThreadStart(void*) + 45
frame #3: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #22, name = 'Dart ThreadPool Worker'
frame #0: 0x00007fff51826916 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007fff518d5040 libsystem_pthread.dylib`_pthread_cond_wait + 701
frame #2: 0x00000001011f4a94 Flutter`dart::Monitor::Wait(long long) + 180
frame #3: 0x00000001013e138a Flutter`dart::BackgroundCompiler::Run() + 1082
frame #4: 0x000000010128246f Flutter`dart::ThreadPool::Worker::Loop() + 47
frame #5: 0x0000000101282312 Flutter`dart::ThreadPool::Worker::Main(unsigned long) + 290
frame #6: 0x00000001011f41ef Flutter`dart::ThreadStart(void*) + 79
frame #7: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #8: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #25, name = 'io.flutter.2.gpu'
frame #0: 0x00007fff51823166 libsystem_kernel.dylib`mach_msg_trap + 10
frame #1: 0x00007fff518236cc libsystem_kernel.dylib`mach_msg + 60
frame #2: 0x00007fff23b0caf5 CoreFoundation`__CFRunLoopServiceMachPort + 197
frame #3: 0x00007fff23b07817 CoreFoundation`__CFRunLoopRun + 1671
frame #4: 0x00007fff23b06e66 CoreFoundation`CFRunLoopRunSpecific + 438
frame #5: 0x0000000100c5586d Flutter`fml::MessageLoopDarwin::Run() + 65
frame #6: 0x0000000100c50330 Flutter`fml::MessageLoopImpl::DoRun() + 22
frame #7: 0x0000000100c54d98 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::Thread::Thread(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0> >(void*) + 170
frame #8: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #9: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
thread #26, name = 'io.flutter.2.io'
frame #0: 0x00007fff51823166 libsystem_kernel.dylib`mach_msg_trap + 10
frame #1: 0x00007fff518236cc libsystem_kernel.dylib`mach_msg + 60
frame #2: 0x00007fff23b0caf5 CoreFoundation`__CFRunLoopServiceMachPort + 197
frame #3: 0x00007fff23b07817 CoreFoundation`__CFRunLoopRun + 1671
frame #4: 0x00007fff23b06e66 CoreFoundation`CFRunLoopRunSpecific + 438
frame #5: 0x0000000100c5586d Flutter`fml::MessageLoopDarwin::Run() + 65
frame #6: 0x0000000100c50330 Flutter`fml::MessageLoopImpl::DoRun() + 22
frame #7: 0x0000000100c54d98 Flutter`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, fml::Thread::Thread(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_0> >(void*) + 170
frame #8: 0x00007fff518d4d36 libsystem_pthread.dylib`_pthread_start + 125
frame #9: 0x00007fff518d158f libsystem_pthread.dylib`thread_start + 15
flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel v1.9.1-hotfixes, v1.9.1+hotfix.6-pre.1, on Mac OS X 10.15.1
19B88, locale zh-Hans-CN)
[!] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
! Some Android licenses not accepted. To resolve this, run: flutter doctor
--android-licenses
[✓] Xcode - develop for iOS and macOS (Xcode 11.1)
[✓] Android Studio (version 3.5)
[✓] VS Code (version 1.40.1)
[✓] Connected device (1 available)
! Doctor found issues in 1 category.
iOS