Thread 1 Queue : com.apple.main-thread (serial) #0 0x000000010348ed9c in __ulock_wait () #1 0x00000001801796d4 in _dlock_wait () #2 0x0000000180179608 in _dispatch_once_wait () #3 0x00000001856950e0 in -[_UIApplicationConfigurationLoader _loadInitializationContext] () #4 0x0000000185695328 in -[_UIApplicationConfigurationLoader applicationInitializationContext] () #5 0x00000001856749f8 in -[_UIScreenInitialDisplayConfigurationLoader initialDisplayContext] () #6 0x0000000185674ca4 in +[UIScreen initialize] () #7 0x000000018006b90c in CALLING_SOME_+initialize_METHOD () #8 0x000000018006c560 in initializeNonMetaClass () #9 0x000000018006e2c0 in initializeAndMaybeRelock () #10 0x000000018007f458 in lookUpImpOrForward () #11 0x0000000180067700 in _objc_msgSend_uncached () #12 0x0000000103ce3e18 in +[Foo load] at /Users/andrew/Developer/tmp/Deadlock3/Deadlock3Tests/Deadlock3Tests.m:43 #13 0x0000000180076614 in load_images () #14 0x00000001035af96c in dyld4::RuntimeState::notifyObjCInit () #15 0x00000001035b468c in dyld4::Loader::runInitializersBottomUp () #16 0x00000001035b77ac in dyld4::Loader::runInitializersBottomUpPlusUpwardLinks(dyld4::RuntimeState&) const::$_0::operator()() const () #17 0x00000001035b473c in dyld4::Loader::runInitializersBottomUpPlusUpwardLinks () #18 0x00000001035c2314 in dyld4::APIs::dlopen_from () #19 0x00000001803e3028 in _CFBundleDlfcnLoadBundle () #20 0x00000001803ae930 in _CFBundleLoadExecutableAndReturnError () #21 0x0000000180e378bc in -[NSBundle loadAndReturnError:] () #22 0x000000010342eb70 in __XCTestBundleInject () #23 0x00000001035b4478 in invocation function for block in dyld4::Loader::findAndRunAllInitializers(dyld4::RuntimeState&) const () #24 0x00000001035d5b18 in invocation function for block in dyld3::MachOAnalyzer::forEachInitializer(Diagnostics&, dyld3::MachOAnalyzer::VMAddrConverter const&, void (unsigned int) block_pointer, void const*) const () #25 0x00000001035cd7e8 in invocation function for block in dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const () #26 0x00000001035cc4bc in dyld3::MachOFile::forEachLoadCommand () #27 0x00000001035cc7c8 in dyld3::MachOFile::forEachSection () #28 0x00000001035cefe4 in dyld3::MachOFile::forEachInitializerPointerSection () #29 0x00000001035d5838 in dyld3::MachOAnalyzer::forEachInitializer () #30 0x00000001035b4334 in dyld4::Loader::findAndRunAllInitializers () #31 0x00000001035b9ef4 in dyld4::JustInTimeLoader::runInitializers () #32 0x00000001035b4698 in dyld4::Loader::runInitializersBottomUp () #33 0x00000001035b77ac in dyld4::Loader::runInitializersBottomUpPlusUpwardLinks(dyld4::RuntimeState&) const::$_0::operator()() const () #34 0x00000001035b473c in dyld4::Loader::runInitializersBottomUpPlusUpwardLinks () #35 0x00000001035c5a54 in dyld4::APIs::runAllInitializersForMain () #36 0x00000001035a5f64 in dyld4::prepare () #37 0x00000001035a565c in _dyld_sim_prepare::$_0::operator()() const () #38 0x00000001035a52a4 in _dyld_sim_prepare () #39 0x0000000102edba8c in dyld4::prepareSim () #40 0x0000000102eda4f0 in dyld4::prepare () #41 0x0000000102ed9ef4 in start () Thread 2 Queue : com.apple.uikit.applicationSupportClient (serial) #0 0x000000010349a190 in __ulock_wait2 () #1 0x0000000103409510 in _os_unfair_lock_lock_slow () #2 0x00000001035c1e98 in dyld4::APIs::dlopen_from () #3 0x0000000238de5c0c in _sl_dlopen () #4 0x000000018748be38 in __getRBSServiceInitializeSymbolLoc_block_invoke () #5 0x0000000187486b50 in +[BSServiceManager sharedInstanceCreatingIfNecessary:] () #6 0x0000000187476748 in +[BSServiceConnection _connectionWithEndpoint:clientContextBuilder:] () #7 0x000000018adffd68 in __44-[UISApplicationSupportClient _remoteTarget]_block_invoke () #8 0x0000000180178de0 in _dispatch_client_callout () #9 0x0000000180188ac8 in _dispatch_lane_barrier_sync_invoke_and_complete () #10 0x000000018adffca0 in -[UISApplicationSupportClient _remoteTarget] () #11 0x000000018adff730 in -[UISApplicationSupportClient applicationInitializationContextWithParameters:] () #12 0x00000001856951fc in __63-[_UIApplicationConfigurationLoader _loadInitializationContext]_block_invoke_2 () #13 0x000000018569514c in __UIAPPLICATION_IS_LOADING_INITIALIZATION_INFO_FROM_THE_SYSTEM__ () #14 0x000000018569512c in __63-[_UIApplicationConfigurationLoader _loadInitializationContext]_block_invoke () #15 0x0000000180178de0 in _dispatch_client_callout () #16 0x000000018017a5d4 in _dispatch_once_callout () #17 0x00000001856950e0 in -[_UIApplicationConfigurationLoader _loadInitializationContext] () #18 0x0000000185695304 in __70-[_UIApplicationConfigurationLoader startPreloadInitializationContext]_block_invoke () #19 0x00000001801774ec in _dispatch_call_block_and_release () #20 0x0000000180178de0 in _dispatch_client_callout () #21 0x000000018018b7dc in _dispatch_root_queue_drain () #22 0x000000018018bf60 in _dispatch_worker_thread2 () #23 0x0000000103bc77d8 in _pthread_wqthread ()