Blank Xamarin watchOS app does not deploy to device - "Execution failed"

Tim Ulbrich 0

When creating an empty Xamarin iOS project via Visual Studio for Mac 2022 "iOS -> App -> Xamarin -> Single View App" and then adding a watchOS project "watchOS -> App -> Xamarin -> WatchKit App" the build is working fine.

Nuget package restore issue could be solved by adding <ReferenceOutputAssembly>false</ReferenceOutputAssembly> to the Watch App Project Reference in the iOS app project file.

The build for all three projects (iOS App, WatchOS Extension, WatchOS App) succeeds without any errors. When trying to deploy the watchOS target to any device, either Simulator or physical Apple Watch, VS just shows "Execution failed" and doesn't give any more detail why it failed.

While researching for a solution we stumpled across a GitHub issue in the xamarin-macios repo that states that watchOS will not be supported with .NET 6. We haven't found an official statement regarding watchOS not being supported anymore. Does that mean it is not possible to deploy a Xamarin watchOS app and also watchOS not supported within MAUI?

Current setup:

Operating System: Mac OS X 12.6.2
Visual Studio Enterprise 2022 for Mac, Version 17.4.3 (build 21)
Runtime: .NET 6.0.12 (64-bit), Architecture: X64
NuGet Version: 6.3.1.1
Xcode 14.2 (21534), Build 14C18
Xamarin.iOS, Version: 16.1.1.27 (Visual Studio Enterprise)

Rob Caplan - MSFT 5,412 Reputation points Microsoft Employee

2023-01-25T19:16:50.1833333+00:00
Please put separate questions in separate threads. You'll have different people looking at your Xamarin question and your roadmap question, and somebody else will follow up on your Xamarin question.

Q&A isn't the right place for roadmap questions. Those should go to the github repo. The github issue you quoted is talking about .Net 6 & Maui and won't immediately affect your Xamarin app. As it says, iOS for .Net does not target watchOS.
This is also noted by watchOS' absence in the .NET Multi-platform App UI (.NET MAUI) Support Policy which

encompasses SDKs for:

Android

iOS

Mac Catalyst

macOS

tvOS
Tim Ulbrich 0 Reputation points

2023-01-26T12:37:53.3766667+00:00

@Rob Caplan - MSFT Thanks for your answer!

To be more precise: The question is how to deploy a Xamarin watchOS app to a physical Apple Watch using .NET 6.

We've ran into several issues with a blank project which most of them we could resolve. Also the "Execution failed" issue as stated in my question above now (sometimes) works. The problem here seems to be Visual Studio on its own switching the Startup Project and it is not reliably working when I choose a Startup project manually that this is saved. With a watchOS example project from the xamarin ios-samples this works better.

However when the execution is not failing and deploying is started we receive
IncorrectArchitecture: Failed to find matching arch for input file: /var/installd/Library/Caches/com.apple.mobile.installd.staging/temp.ke1b2v/extracted/WatchConnectivityOnWatch.app/PlugIns/WatchConnectivityOnWatchExtension.appex/WatchConnectivityOnWatchExtension

error MT1006: Could not install the application '/Users/tulbrich/Downloads/ios-samples-main/watchOS/WatchConnectivity/WatchConnectivity/bin/iPhone/Release/WatchConnectivity.app' on the device 'iPhone von Tim': AMDeviceSecureInstallApplicationBundle returned: 0xe8000087 (kAMDIncorrectArchitectureError).

Trying the workaround mentioned in this Github Issue did not fix it.

Running into all these errors lead to us thinking about whether deploying Xamarin watchOS apps using .NET 6 is even possible.