I was able to reproduce this on iOS 17 by animating the view transitions by changing the top level MyApp to: @main struct MyApp: App { @State private var store = Store() var body: some Scene { WindowGroup { if store.shown { ContentView() .transition(.move(edge: .bottom)) } else { EmptyView() .transition(.move(edge: .bottom)) } } .environment(store) } } and the DetailView to: struct DetailView: View { @Environment(Store.self) private var store var body: some View { Button("Pop to top") { withAnimation { store.shown = false } } .task { print("DetailView task executed") } .onAppear { print("DetailView appeared") } .onDisappear { print("DetailView disappeared") } } } By the way, this only happens in this simple reproducer if the DetailView is shown from the ContentView within the NavigationView.

A reboot fixed mine.

Found the solution: https://stackoverflow.com/questions/76110049/xcode-simulator-targets-show-rosetta

Looks like it's downloading VERY slowly and the progress within the App Store application doesn't match the progress of the Xcode.app progress wheel in from Finder in the Applications folder. It's been downloading/updating for 6 hours...almost done.

Intel-based Big Sur here with same issue. I installed another app at the same time and it hung as well. After rebooting, the other app said it was done but Xcode was still hung.

I get the same thing a LOT when I background an app with a map showing. My map has several circular regions and a current location marker.

I just confirmed that the project runs fine on my non-Catalina system. This issue arised after updating to 10.15.2.On non-Catalina system, I am running Xcode 11.3 and everything is fine.

#00x00007fff523d5bea in __abort_with_payload ()#10x00007fff523d74f3 in abort_with_payload_wrapper_internal ()#20x00007fff523d74a3 in abort_with_reason ()#30x00007fff52469974 in pthread_self.cold.1 ()#40x00007fff52462fe3 in pthread_self ()#50x000000010f3f316b in __tsan::cur_thread() ()#60x000000010f3c8985 in wrap_sysctlbyname ()#70x00007fff52470331 in assert_simulator_supported_host ()#80x00007fff4ff167c1 in libSystem_initializer ()#90x000000010f2fa3a7 in ImageLoaderMachO::doModInitFunctions(ImageLoader::LinkContext const&) ()#100x000000010f2fa7b8 in ImageLoaderMachO::doInitialization(ImageLoader::LinkContext const&) ()#110x000000010f2f59a2 in ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) ()#120x000000010f2f590f in ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) ()#130x000000010f2f590f in ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) ()#140x000000010f2f590f in ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) ()#150x000000010f2f47a6 in ImageLoader::processInitializers(ImageLoader::LinkContext const&, unsigned int, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) ()#160x000000010f2f4846 in ImageLoader::runInitializers(ImageLoader::LinkContext const&, ImageLoader::InitializerTimingList&) ()#170x000000010f2e9046 in dyld::initializeMainExecutable() ()#180x000000010f2ed0fc in dyld::_main(macho_header const*, unsigned long, int, char const**, char const**, char const**, unsigned long*) ()#190x000000010f2e81cd in start_sim ()#200x000000011db508cc in dyld::useSimulatorDyld(int, macho_header const*, char const*, int, char const**, char const**, char const**, unsigned long*, unsigned long*) ()#210x000000011db4e575 in dyld::_main(macho_header const*, unsigned long, int, char const**, char const**, char const**, unsigned long*) ()#220x000000011db49227 in dyldbootstrap::start(dyld3::MachOLoaded const*, int, char const**, dyld3::MachOLoaded const*, unsigned long*) ()#230x000000011db49025 in _dyld_start ()