Project build with Widget using AdditionalAppExtensions fails: The source '....appex' does not exist.

[Toine-db]

Apple platform

iOS

Framework version

net9.0-*

Affected platform version

VS2022 version 17.14.8, XCode 16.4, dotnet Workload 9.0.204

Description

Expected Behavior

Build MAUI iOS app with Widget (using AdditionalAppExtensions) with exact location to widget appex (relative or absolute path).

Actual Behavior

Build from Visual Studio on Windows can't find appex in given location, while it works on VSCode on MAC.

Error:
C:\Program Files\dotnet\packs\Microsoft.iOS.Sdk.net9.0_18.4\18.4.9288\tools\msbuild\Xamarin.Shared.targets(2681,3): error : The source '.................../SwiftExtension/Build/Products/Debug-iphoneos/MyCustomWidgetExtension.appex' does not exist.

Steps to Reproduce

1. Create SwiftUI Widget in Xcode
2. Create MAUI app for iOS
   a. optional: implement Entitlements.plist (with com.apple.security.application-groups) for shared app group with Widget
3. Add widget appex with AdditionalAppExtensions in csproj
4. Pair with Mac and build

Example repo: https://github.com/Toine-db/Maui.Issue.Ios.AdditionalAppExtensions-

Did you find any workaround?

Build on MacOS with VSCode

Build logs

1>Target _DecompressPlugIns:
1> Skipping target "_DecompressPlugIns" because it has no outputs.
1>Target _DecompressXpcServices:
1> Skipping target "_DecompressXpcServices" because it has no outputs.
1>Target _CopyDirectoriesToBundle:
1> Skipping target "_CopyDirectoriesToBundle" because it has no outputs.
1>Target _CopyAppExtensionsToBundle:
1> Creating directory "bin\Debug\net9.0-ios\ios-arm64\device-builds\iphone15.2-18.5/MauiAppX.app\PlugIns".
1> Creating directory "bin/Debug/net9.0-ios/ios-arm64/device-builds/iphone15.2-18.5/MauiAppX.app/PlugIns".
1> C:\Program Files\dotnet\packs\Microsoft.iOS.Sdk.net9.0_18.4\18.4.9288\tools\msbuild\Xamarin.Shared.targets(2681,3): error : The source 'D:/repos/Maui.Issue.Ios.AdditionalAppExtensions-/MauiAppX/../SwiftExtension/Build/Products/Debug-iphoneos/MyCustomWidgetExtension.appex' does not exist.
1> [xma][info]: MqttClient - Disconnected.
1>Done building target "_CopyAppExtensionsToBundle" in project "MauiAppX.csproj" -- FAILED.
1>
1>Done building project "MauiAppX.csproj" -- FAILED.
1>
1>Build FAILED.