Xamarin-macios: [Xcode11] [Simulator] Updating to Xcode 11 stops the simulator from launching.

[mandel-macaque]

After updating to Xcode 11 beta 1 every time that a simulator is tried to be launched the following exception is thrown resulting in no simulator running. This happens with all simulators.

Exception

Foundation.ObjCException: NSInvalidArgumentException: -[SimDevice registerNotificationHandler:]: unrecognized selector sent to instance 0x7ffbf5d1e110

Workaround

Until there is fix, the following steps can be followed to re-install the old simulator framework to allow developers to continue their work:

1. Ensure that you have Xcode 11 selected via xcode-select:
   sudo xcode-select -s /Applications/Xcode11-beta1.app/Contents/Developer/
2. Run, if needed, the setup tools for the first time.
   `/Applications/Xcode11-beta1.app/Contents/Developer/usr/bin/xcodebuild -runFirstLaunch
3. Remove the following framework:
   sudo rm -Rf /Library/Developer/PrivateFrameworks/CoreSimulator.framework/Versions/*
4. Switch back to the old Xcode version
   sudo xcode-select -s /Applications/Xcode102.app/Contents/Developer/
5. Re-run the first launch tool for the _OLD_ Xcode version you just selected
   /Applications/Xcode102.app/Contents/Developer/usr/bin/xcodebuild -runFirstLaunch

After following the above steps, you should be able to work with simulator again.

VS bug #916235

[Uncommon]

Another workaround is to launch the simulator manually from Xcode 10.2. Visual Studio will then use that instance of the simulator for debugging.

[mandel-macaque]

@Uncommon nice catch, I did not try that, thx!

[spouliot]

re-opening (it's sync'ed with vsts)

[nschoenberg]

Is this issue really closed? I have it with Xcode 11.0 beta 5 and can't make my simulator work. Compiling of app works

[maculit]

@nschoenberg were you able to use the simulator with Xcode 11?

[nschoenberg]

@maculit with the newest version of xcode 11.1 the problem ist solved on my side.

[lselbeck]

Seeing the same issue with Xcode v11.2.1

[rolfbjarne]

@lselbeck which version of Xamarin.iOS are you using? And what's the exact output?

[lselbeck]

@rolfbjarne Xamarin.iOS v13.6.0.12, output:
```SetUp : Xamarin.UITest.XDB.Exceptions.DeviceAgentException : Failed to launch simulator

ExitCode: 134
0 CoreFoundation 0x00007fff4dcc6acd __exceptionPreprocess + 256
1 libobjc.A.dylib 0x00007fff783c8a17 objc_exception_throw + 48
10 FBSimulatorControl 0x000000010694f576 +[FBSimulator fromSimDevice:configuration:launchdSimProcess:containerApplicationProcess:set:] + 598
11 FBSimulatorControl 0x0000000106952aad -[FBSimulatorInflationStrategy inflateSimulators:availableDevices:previouslyIdentifiedContainerApplications:] + 1085
12 FBSimulatorControl 0x0000000106952588 -[FBSimulatorInflationStrategy inflateFromDevices:exitingSimulators:] + 1208
13 FBSimulatorControl 0x00000001069177f1 -[FBSimulatorSet allSimulators] + 145
14 FBSimulatorControl 0x000000010691508d -[FBSimulatorSet query:] + 173
15 iOSDeviceManager 0x00000001066f6f0b +[Simulator withID:] + 246
16 iOSDeviceManager 0x00000001066ef37d +[Device withID:] + 118
17 iOSDeviceManager 0x00000001066f27a8 +[Command simulatorFromArgs:] + 163
18 iOSDeviceManager 0x00000001066feb4c +[LaunchSimulatorCommand execute:] + 20
19 iOSDeviceManager 0x00000001066f51ee +[CLI process:] + 1111
2 CoreFoundation 0x00007fff4dd408d6 -[NSObject(NSObject) __retain_OA] + 0
20 iOSDeviceManager 0x00000001066e0609 main + 121
21 libdyld.dylib 0x00007fff79b973d5 start + 1
3 CoreFoundation 0x00007fff4dc6893f ___forwarding___ + 1485
4 CoreFoundation 0x00007fff4dc682e8 _CF_forwarding_prep_0 + 120
5 FBSimulatorControl 0x000000010693cad9 -[FBCoreSimulatorNotifier initWithNotifier:queue:block:] + 377
6 FBSimulatorControl 0x000000010693c7cc +[FBCoreSimulatorNotifier notifierForSimDevice:queue:block:] + 188
7 FBSimulatorControl 0x000000010694b3fb -[FBSimulatorEventRelay createNotifierForSimDevice:] + 251
8 FBSimulatorControl 0x0000000106949902 -[FBSimulatorEventRelay initWithSimDevice:launchdProcess:containerApplication:processFetcher:queue:sink:] + 594
9 FBSimulatorControl 0x000000010694fba2 -[FBSimulator attachEventSinkCompositionWithLaunchdSimProcess:containerApplicationProcess:] + 754
(
)
* First throw call stack:
2019-11-14 10:00:11.651 iOSDeviceManager[54190:789807] -[SimDeviceNotificationManager registerNotificationHandler:]: unrecognized selector sent to instance 0x7f93036021c0
2019-11-14 10:00:11.652 iOSDeviceManager[54190:789807] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[SimDeviceNotificationManager registerNotificationHandler:]: unrecognized selector sent to instance 0x7f93036021c0'
libc++abi.dylib: terminating with uncaught exception of type NSException```

[rolfbjarne]

@lselbeck that doesn't come from any tool shipped from this repository. Exactly where did you see that and what did you do to see it?

[lselbeck]

This is on VS for Mac v8.3.8 when attempting to run NUnit v2.6.4 tests on a Xamarin.iOS project. The failing line being
c# return Xamarin.UITest.ConfigureApp.iOS.StartApp();

[mridoni]

Same issue here with Xcode 11.2.1

[rolfbjarne]

@lselbeck I believe Xamarin.IOTest is AppCenter, and this describes how to report bugs with them: https://docs.microsoft.com/en-us/appcenter/help

[scotthyphen]

Looks like this issue is fixed but why would I still get this error message today?

The app has been terminated.
Launch failed. The app 'xxxxxx' could not be launched on 'xxxxx'. Error: error MT1008: Failed to launch the simulator: NSInvalidArgumentException: -[SimDevice registerNotificationHandler:]: unrecognized selector sent to instance 0x7f85be228c70.

I'm running VS 15.9.20 and Xcode 11.3.1. I did upgrade to Xcode 11 recently. Any input greatly appreciated.