[msbuild] Make sure the build doesn't keep going if the ILLink task fails.

[rolfbjarne]

Here's an example failure that didn't stop the build:

Target Name=_RunILLink Project=sampleproj.csproj
    Building target "_RunILLink" completely.
    Output file "obj\Release\net8.0-ios\ios-arm64\linked\Link.semaphore" does not exist.
    [...]
    Xamarin.MacDev.Tasks.ILLink
        [...]
        C:\Program Files\dotnet\packs\Microsoft.iOS.Windows.Sdk.net8.0_17.5\17.5.8030\tools\msbuild\iOS\Xamarin.iOS.Common.After.targets(364,3): [xma][err]: An exception occurred in the task 'ILLink'
        C:\Program Files\dotnet\packs\Microsoft.iOS.Windows.Sdk.net8.0_17.5\17.5.8030\tools\msbuild\iOS\Xamarin.iOS.Common.After.targets(364,3): The post for client build1460814608Ilian on topic xvs/build/1.14.0.6/execute-task/ecacau/de6ed16002fILLink has been cancelled
   at Xamarin.Messaging.Client.MessagingClient.PostAsync[TRequest,TResponse](TRequest message, String topic, MessagePriority priority, CancellationToken cancellationToken, Boolean retain, Int32 timeoutSecs) in D:\a\_work\1\s\src\Xamarin.Messaging.Client\MessagingClient.cs:line 231
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.ExecuteWithRetryAsync[TResult](Func`1 executeDelegate, IMessagingAnalyticsAction analytics, Int32 attempts) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 57
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.ThrowIfConnected(ExceptionDispatchInfo exceptionInfo, IMessagingAnalyticsAction analytics) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 149
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.HandleExceptionAsync[TResult](ExceptionDispatchInfo exceptionInfo, Func`1 reentrancyDelegate, IMessagingAnalyticsAction analytics, Int32 attempts) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 97
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.ExecuteWithRetryAsync[TResult](Func`1 executeDelegate, IMessagingAnalyticsAction analytics, Int32 attempts) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 64
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.HandleExceptionAsync[TResult](ExceptionDispatchInfo exceptionInfo, Func`1 reentrancyDelegate, IMessagingAnalyticsAction analytics, Int32 attempts) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 103
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.ExecuteWithRetryAsync[TResult](Func`1 executeDelegate, IMessagingAnalyticsAction analytics, Int32 attempts) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 64
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.ExecuteWithRetryAsync[TResult](Func`1 executeDelegate, Int32 attempts) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 39
   at Xamarin.Messaging.Ssh.MessagingClientPro.PostAsync[TMessage,TResult](TMessage request, CancellationToken cancellationToken, Boolean retain, Int32 timeoutSecs) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingClientPro.cs:line 144
   at Xamarin.Messaging.Build.Client.BuildClient.RunMessagingAsync[TMessage,TResult](TMessage message, Int32 timeoutSecs) in D:\a\_work\1\s\src\MSBuild\Xamarin.Messaging.Build.Client\BuildClient.cs:line 293
   at Xamarin.Messaging.Build.Client.BuildClient.ExecuteTaskAsync(String task, String inputs) in D:\a\_work\1\s\src\MSBuild\Xamarin.Messaging.Build.Client\BuildClient.cs:line 65
   at Xamarin.Messaging.Build.Client.TaskRunner.RunAsync(Task task) in D:\a\_work\1\s\src\MSBuild\Xamarin.Messaging.Build.Client\TaskRunner.cs:line 56
        Errors
            C:\Program Files\dotnet\packs\Microsoft.iOS.Windows.Sdk.net8.0_17.5\17.5.8030\tools\msbuild\iOS\Xamarin.iOS.Common.After.targets(364,3): MessagingException: The post for client build1460814608Ilian on topic xvs/build/1.14.0.6/execute-task/ecacau/de6ed16002fILLink has been cancelled
OperationCanceledException: The operation was canceled.
 [sampleproj.csproj]
            C:\Program Files\dotnet\packs\Microsoft.iOS.Windows.Sdk.net8.0_17.5\17.5.8030\tools\msbuild\iOS\Xamarin.iOS.Common.After.targets(364,3): error MSB4018: The "Xamarin.MacDev.Tasks.ILLink" task failed unexpectedly.
System.AggregateException: One or more errors occurred. (One or more errors occurred. (An error occurred while executing the operation and the connection could not be reestablished))
 ---> System.AggregateException: One or more errors occurred. (An error occurred while executing the operation and the connection could not be reestablished)
 ---> Xamarin.Messaging.Exceptions.MessagingException: An error occurred while executing the operation and the connection could not be reestablished
 ---> Xamarin.Messaging.Exceptions.ClientDisconnectedException: The client build1460814608Ilian has been disconnected while waiting a post response to topic xma/agents
   at Xamarin.Messaging.Client.MessagingClient.PostAsync[TRequest,TResponse](TRequest message, String topic, MessagePriority priority, CancellationToken cancellationToken, Boolean retain, Int32 timeoutSecs) in D:\a\_work\1\s\src\Xamarin.Messaging.Client\MessagingClient.cs:line 197
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.ExecuteWithRetryAsync[TResult](Func`1 executeDelegate, IMessagingAnalyticsAction analytics, Int32 attempts) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 57
   --- End of inner exception stack trace ---
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.ReconnectAsync(ExceptionDispatchInfo exceptionInfo, IMessagingAnalyticsAction analytics) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 182
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.HandleExceptionAsync[TResult](ExceptionDispatchInfo exceptionInfo, Func`1 reentrancyDelegate, IMessagingAnalyticsAction analytics, Int32 attempts) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 99
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.ExecuteWithRetryAsync[TResult](Func`1 executeDelegate, IMessagingAnalyticsAction analytics, Int32 attempts) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 64
   at Xamarin.Messaging.Ssh.MessagingRunnerPro.ExecuteWithRetryAsync[TResult](Func`1 executeDelegate, Int32 attempts) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingRunnerPro.cs:line 39
   at Xamarin.Messaging.Ssh.MessagingClientPro.PostAsync[TMessage,TResult](TMessage request, Boolean retain, Int32 timeoutSecs) in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingClientPro.cs:line 135
   at Xamarin.Messaging.Ssh.MessagingService.RefreshAgentsStatusAsync() in D:\a\_work\1\s\src\Xamarin.Messaging.Ssh\MessagingService.cs:line 298
   at Xamarin.Messaging.Build.Client.BuildConnection.GetBuildAgentStatusAsync() in D:\a\_work\1\s\src\MSBuild\Xamarin.Messaging.Build.Client\BuildConnection.Normal.cs:line 435
   at Xamarin.Messaging.Build.Client.BuildConnection.IsBuildAgentRunningAsync() in D:\a\_work\1\s\src\MSBuild\Xamarin.Messaging.Build.Client\BuildConnection.Normal.cs:line 92
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at Xamarin.Messaging.Build.Client.BuildConnection.get_IsConnected() in D:\a\_work\1\s\src\MSBuild\Xamarin.Messaging.Build.Client\BuildConnection.Normal.cs:line 45
   at Xamarin.Messaging.Build.Client.BuildConnection.GetAsync(IBuildEngine4 engine) in D:\a\_work\1\s\src\MSBuild\Xamarin.Messaging.Build.Client\BuildConnection.Static.cs:line 50
   at Xamarin.Messaging.Build.Client.TaskRunner.DisconnectAsync(Task task) in D:\a\_work\1\s\src\MSBuild\Xamarin.Messaging.Build.Client\TaskRunner.cs:line 541
   at Xamarin.Messaging.Build.Client.TaskRunner.RunAsync(Task task) in D:\a\_work\1\s\src\MSBuild\Xamarin.Messaging.Build.Client\TaskRunner.cs:line 99
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at Xamarin.MacDev.Tasks.ILLink.Execute() in /Users/builder/azdo/_work/1/s/xamarin-macios/msbuild/Xamarin.MacDev.Tasks/Tasks/ILLink.cs:line 30
   at Microsoft.Build.BackEnd.TaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(TaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask)
        Messages
        [...]
    Task "Touch" skipped, due to false condition; ( '$(_ILLinkExitCode)' == '0' ) was evaluated as ( '' == '0' ).

 (and build kept going, eventually failing later on because ILLink didn't run correctly)

Ref: https://developercommunity.visualstudio.com/t/Maui-Blazor-Hybrid-App-wont-publish-to-/10750311#T-ND10763338

[vs-mobiletools-engineering-service2]

✅ API diff for current PR / commit

NET (empty diffs)

• iOS: (empty diff detected)
• tvOS: (empty diff detected)
• MacCatalyst: (empty diff detected)
• macOS: (empty diff detected)

✅ API diff vs stable

.NET (No breaking changes)

• iOS: vsdrops gist (No breaking changes)
• tvOS: vsdrops gist (No breaking changes)
• MacCatalyst: vsdrops gist (No breaking changes)
• macOS: vsdrops gist (No breaking changes)

ℹ️ Generator diff

Generator Diff: vsdrops (html) vsdrops (raw diff) gist (raw diff) - Please review changes)

Pipeline on Agent
Hash: 15c77422d903518cdccaab5a26d02fa1cf396b8e [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build] Tests on macOS X64 - Mac Sonoma (14) passed 💻

✅ All tests on macOS X64 - Mac Sonoma (14) passed.

Pipeline on Agent
Hash: 15c77422d903518cdccaab5a26d02fa1cf396b8e [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build] Windows Integration Tests passed 💻

✅ All Windows Integration Tests passed.

Pipeline on Agent
Hash: 15c77422d903518cdccaab5a26d02fa1cf396b8e [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build] Tests on macOS M1 - Mac Ventura (13) passed 💻

✅ All tests on macOS M1 - Mac Ventura (13) passed.

Pipeline on Agent
Hash: 15c77422d903518cdccaab5a26d02fa1cf396b8e [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build] Tests on macOS M1 - Mac Monterey (12) passed 💻

✅ All tests on macOS M1 - Mac Monterey (12) passed.

Pipeline on Agent
Hash: 15c77422d903518cdccaab5a26d02fa1cf396b8e [PR build]

[vs-mobiletools-engineering-service2]

🚀 [CI Build] Test results 🚀

Test results

✅ All tests passed on VSTS: test results.

🎉 All 101 tests passed 🎉

Tests counts

✅ cecil: All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (iOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (MacCatalyst): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (macOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (Multiple platforms): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (tvOS): All 1 tests passed. Html Report (VSDrops) Download
✅ framework: All 2 tests passed. Html Report (VSDrops) Download
✅ fsharp: All 4 tests passed. Html Report (VSDrops) Download
✅ generator: All 1 tests passed. Html Report (VSDrops) Download
✅ interdependent-binding-projects: All 4 tests passed. Html Report (VSDrops) Download
✅ introspection: All 4 tests passed. Html Report (VSDrops) Download
✅ linker: All 40 tests passed. Html Report (VSDrops) Download
✅ monotouch (iOS): All 7 tests passed. Html Report (VSDrops) Download
✅ monotouch (MacCatalyst): All 10 tests passed. Html Report (VSDrops) Download
✅ monotouch (macOS): All 9 tests passed. Html Report (VSDrops) Download
✅ monotouch (tvOS): All 7 tests passed. Html Report (VSDrops) Download
✅ msbuild: All 2 tests passed. Html Report (VSDrops) Download
✅ xcframework: All 4 tests passed. Html Report (VSDrops) Download
✅ xtro: All 1 tests passed. Html Report (VSDrops) Download

Pipeline on Agent
Hash: 15c77422d903518cdccaab5a26d02fa1cf396b8e [PR build]

[stephen-hawley]

Is there a reason why this is the case? Does ILLink need a fix and if so, is there an issue for it?

[rolfbjarne]

There are any number of reasons the ILLink task may fail for legitimate reasons, an easy one being that the network went down.