[release/11.0.1xx-preview3] Make CoreCLR the default runtime for debug builds. by rolfbjarne · Pull Request #25051 · dotnet/macios

rolfbjarne · 2026-03-31T14:33:28Z

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…g builds.

Copilot

Pull request overview

Updates the SDK defaults to make CoreCLR the default runtime for debug builds (instead of Mono), aligning debug behavior with the intended runtime selection.

Changes:

Adds a new defaulting rule for UseMonoRuntime intended to switch debug builds to CoreCLR.
Keeps existing defaulting rules for macOS and NativeAOT unchanged.

Copilot · 2026-03-31T14:36:34Z

dotnet/targets/Xamarin.Shared.Sdk.props

 		-->
 		<_UseNativeAot Condition="'$(PublishAot)' == 'true' And '$(_IsPublishing)' == 'true'">true</_UseNativeAot>

+		<UseMonoRuntime Condition=" '$(UseMonoRuntime)' == '' And '$(_BundlerDebug)' == 'true'">false</UseMonoRuntime>


The new default UseMonoRuntime condition depends on $(_BundlerDebug), but _BundlerDebug is only computed later in dotnet/targets/Xamarin.Shared.Sdk.targets (before importing Microsoft.NET.Sdk). Since this file is a .props imported earlier, $(_BundlerDebug) will typically still be empty here, so this condition won’t fire and debug builds will continue to default to Mono. Consider basing the default on $(Configuration) == 'Debug' (and/or $(MtouchDebug)/$(MmpDebug) if those are set early), or move the UseMonoRuntime defaulting logic to a location where _BundlerDebug is already defined (and ensure dependent property groups still evaluate as intended).

Suggested change

<UseMonoRuntime Condition=" '$(UseMonoRuntime)' == '' And '$(_BundlerDebug)' == 'true'">false</UseMonoRuntime>

<UseMonoRuntime Condition=" '$(UseMonoRuntime)' == '' And '$(Configuration)' == 'Debug'">false</UseMonoRuntime>

vs-mobiletools-engineering-service2 · 2026-04-02T07:40:16Z

✅ [CI Build #4db2099] Build passed (Build packages) ✅

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Hash: 4db2099e9f86576bca72ca495ce7f75af53c01bf [PR build]

vs-mobiletools-engineering-service2 · 2026-04-02T07:45:41Z

✅ [PR Build #4db2099] Build passed (Detect API changes) ✅

Pipeline on Agent
Hash: 4db2099e9f86576bca72ca495ce7f75af53c01bf [PR build]

vs-mobiletools-engineering-service2 · 2026-04-02T07:58:47Z

✅ API diff for current PR / commit

NET (empty diffs)

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

✅ API diff vs stable

NET (empty diffs)

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

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

Pipeline on Agent
Hash: 4db2099e9f86576bca72ca495ce7f75af53c01bf [PR build]

vs-mobiletools-engineering-service2 · 2026-04-02T08:07:23Z

✅ [CI Build #4db2099] Build passed (Build macOS tests) ✅

Pipeline on Agent
Hash: 4db2099e9f86576bca72ca495ce7f75af53c01bf [PR build]

vs-mobiletools-engineering-service2 · 2026-04-02T10:19:17Z

🔥 [CI Build #4db2099] Test results 🔥

Test results

❌ Tests failed on VSTS: test results

0 tests crashed, 11 tests failed, 150 tests passed.

Failures

❌ dotnettests tests (iOS)

1 tests failed, 0 tests passed.

Failed tests

DotNet tests: Failed (Execution failed with exit code 1)
- Xamarin.Tests.BundleStructureTest.Build(iOS,"ios-arm64",All,"Deb...: No unexpected files
  Expected:
  But was: < "Frameworks/BundleStructure.framework", "Frameworks/BundleStructure.fram...
- Xamarin.Tests.BundleStructureTest.Build(iOS,"iossimulator-x64",A...: No unexpected files
  Expected:
  But was: < "Frameworks/BundleStructure.framework", "Frameworks/BundleStructure.fram...
- Xamarin.Tests.DotNetProjectTest.BuildProjectsWithExtensions(iOS,...: 'dotnet build' failed with exit code 1
  Full command: /Users/builder/azdo/_work/3/s/macios/builds/downloads/dotnet-sdk-11.0.100-p...
- ... and 19 more

Html Report (VSDrops) Download

❌ dotnettests tests (MacCatalyst)

1 tests failed, 0 tests passed.

Failed tests

DotNet tests: Failed (Execution failed with exit code 1)
- Xamarin.Tests.BundleStructureTest.Build(MacCatalyst,"maccatalyst...: No unexpected files
  Expected:
  But was: < "Contents/MonoBundle/.xamarin/maccatalyst-arm64/FrameworksInRuntimesNati...
- Xamarin.Tests.BundleStructureTest.Build(MacCatalyst,"maccatalyst...: No unexpected files
  Expected:
  But was: < "Contents/MonoBundle/BundleStructure.r2r.dylib", "Contents/MonoBundle/li...
- Xamarin.Tests.DotNetProjectTest.CustomizedCodeSigning(MacCatalys...: Unsigned: /Users/builder/azdo/_work/1/s/macios/tests/dotnet/CustomizedCodeSigning/MacCatalyst/bin/Debug/net11.0-maccatalyst/ma...
- ... and 7 more

Html Report (VSDrops) Download

❌ dotnettests tests (tvOS)

1 tests failed, 0 tests passed.

Failed tests

DotNet tests: Failed (Execution failed with exit code 1)
- Xamarin.Tests.BundleStructureTest.Build(TVOS,"tvos-arm64",All,"D...: No unexpected files
  Expected:
  But was: < "Frameworks/BundleStructure.framework", "Frameworks/BundleStructure.fram...
- Xamarin.Tests.DotNetProjectTest.DedupEnabledTest(TVOS,"tvos-arm6...: Dedup optimization should be enabled for AOT compilation on: TVOS with RID: tvos-arm64
  Expected: True
  But was: False
- Xamarin.Tests.DotNetProjectTest.DedupEnabledTest(TVOS,"tvos-arm6...: Dedup optimization should be enabled for AOT compilation on: TVOS with RID: tvos-arm64
  Expected: True
  But was: False
- ... and 4 more

Html Report (VSDrops) Download

❌ linker tests

1 tests failed, 43 tests passed.

Failed tests

link all/iOS - simulator/Release: HarnessException (Harness exception for 'link all': System.AggregateException: One or more errors occurred. (A task was canceled.)
---> System.Threading.Tasks.TaskCanceledException: A task was canceled.
at System.Threading.Tasks.Task.GetExceptions(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task1.GetResultCore(Boolean waitCompletionNotification) at Microsoft.DotNet.XHarness.iOS.Shared.TestReporter.get_TestExecutionStarted() at Microsoft.DotNet.XHarness.iOS.Shared.TestReporter.ParseResult() at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at Microsoft.DotNet.XHarness.iOS.Shared.TestReporter.ParseResult() at Xharness.AppRunner.RunAsync() in /Users/builder/azdo/_work/1/s/macios/tests/xharness/AppRunner.cs:line 424 at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Runtime.CompilerServices.AsyncTaskMethodBuilder1.AsyncStateMachineBox1.MoveNext(Thread threadPoolThread) at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox box, Boolean allowInlining) at System.Threading.Tasks.Task.RunContinuations(Object continuationObject) at Microsoft.DotNet.XHarness.Common.Execution.ProcessManager.ExecuteCommandAsync(String filename, IList1 args, ILog log, ILog stdout, ILog stderr, TimeSpan timeout, Dictionary2 environmentVariables, Nullable1 cancellationToken)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder1.AsyncStateMachineBox1.MoveNext()
at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox box, Boolean allowInlining)
at System.Threading.Tasks.Task.RunContinuations(Object continuationObject)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder1.SetExistingTaskResult(Task1 task, TResult result)
at Microsoft.DotNet.XHarness.Common.Execution.ProcessManager.RunAsyncInternal(Process process, ILog log, ILog stdout, ILog stderr, Action2 kill, Func3 getChildProcessIds, Nullable1 timeout, Dictionary2 environmentVariables, Nullable1 cancellationToken, Nullable1 diagnostics)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder1.AsyncStateMachineBox1.MoveNext()
at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox box, Boolean allowInlining)
at System.Threading.Tasks.Task.RunContinuations(Object continuationObject)
at Microsoft.DotNet.XHarness.Common.Execution.ProcessManager.WaitForExitAsync(Process process, Nullable1 timeout) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Runtime.CompilerServices.AsyncTaskMethodBuilder1.AsyncStateMachineBox1.MoveNext() at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox box, Boolean allowInlining) at System.Threading.Tasks.Task.RunContinuations(Object continuationObject) at Microsoft.DotNet.XHarness.Common.Utilities.Extensions.TimeoutAfter[T](Task1 task, TimeSpan timeout)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder1.AsyncStateMachineBox1.MoveNext()
at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox box, Boolean allowInlining)
at System.Threading.Tasks.Task.RunContinuations(Object continuationObject)
at System.Threading.Tasks.Task.TwoTaskWhenAnyPromise`1.Invoke(Task completingTask)
at System.Threading.Tasks.Task.RunContinuations(Object continuationObject)
at System.Diagnostics.Process.OnExited()
at System.Threading._ThreadPoolWaitOrTimerCallback.WaitOrTimerCallback_Context_f(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.CompleteWaitThreadPoolWorkItem.System.Threading.IThreadPoolWorkItem.Execute()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart()
at System.Threading.Thread.StartCallback()
--- End of stack trace from previous location ---

--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
at Microsoft.DotNet.XHarness.iOS.Shared.TestReporter.get_TestExecutionStarted()
at Microsoft.DotNet.XHarness.iOS.Shared.TestReporter.ParseResult()
at Xharness.AppRunner.RunAsync() in /Users/builder/azdo/_work/1/s/macios/tests/xharness/AppRunner.cs:line 424
at Xharness.Jenkins.TestTasks.RunSimulator.RunTestAsync() in /Users/builder/azdo/_work/1/s/macios/tests/xharness/Jenkins/TestTasks/RunSimulator.cs:line 123
at Xharness.Jenkins.TestTasks.RunTest.ExecuteAsync() in /Users/builder/azdo/_work/1/s/macios/tests/xharness/Jenkins/TestTasks/RunTest.cs:line 113
at Xharness.Jenkins.TestTasks.TestTasks.RunInternalAsync() in /Users/builder/azdo/_work/1/s/macios/tests/xharness/Jenkins/TestTasks/TestTask.cs:line 234)

Html Report (VSDrops) Download

❌ monotouch tests (iOS)

2 tests failed, 13 tests passed.

Failed tests

monotouch-test/iOS - simulator/Release (all optimizations): Crashed
monotouch-test/iOS - simulator/Release (managed static registrar, all optimizations): TimedOut

Html Report (VSDrops) Download

❌ monotouch tests (MacCatalyst)

2 tests failed, 17 tests passed.

Failed tests

monotouch-test/Mac Catalyst/Release (NativeAOT): Failed (Test run failed.
Tests run: 3729 Passed: 3560 Inconclusive: 10 Failed: 1 Ignored: 168)
monotouch-test/Mac Catalyst/Release (static registrar): Failed (Test run failed.
Tests run: 3729 Passed: 3569 Inconclusive: 10 Failed: 2 Ignored: 158)

Html Report (VSDrops) Download

❌ windows tests

1 tests failed, 2 tests passed.

Failed tests

Remote .NET tests/Xamarin.Tests.WindowsTest.PluralRuntimeIdentifiersWithRemoteMac(iOS,"ios-arm64"): Failed: 'dotnet build' failed with exit code 1
Remote .NET tests/Xamarin.Tests.WindowsTest.BundleStructureWithRemoteMac(iOS,"ios-arm64",All,"Debug"): Failed: No unexpected files
Remote .NET tests/Xamarin.Tests.IncrementalBuildTest.CodeChangeSkipsTargetsOnRemoteWindows(iOS,"iossimulator-arm64",False): Failed: The target '_LinkNativeExecutable' was not executed: the target was found 1 time(s) in the binlog, but they were all skipped (B)

Html Report (VSDrops) Download

❌ Tests on macOS Sequoia (15) tests

1 tests failed, 4 tests passed.

Failed tests

monotouch-test: Failed

Html Report (VSDrops) Download

❌ Tests on macOS Tahoe (26) tests

1 tests failed, 4 tests passed.

Failed tests

monotouch-test: Failed
- SslCertificatesWithoutOCSPEndPointsNSUrlSessionHandler_AllowByDefault("https://sha256.badssl.com/") : Validation Callback called
- SslCertificatesWithoutOCSPEndPointsNSUrlSessionHandler_AllowByDefault("https://sha256.badssl.com/") : Validation Callback called

Html Report (VSDrops) Download

Successes

✅ cecil: 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
✅ framework: All 2 tests passed. Html Report (VSDrops) Download
✅ fsharp: All 4 tests passed. Html Report (VSDrops) Download
✅ generator: All 5 tests passed. Html Report (VSDrops) Download
✅ interdependent-binding-projects: All 4 tests passed. Html Report (VSDrops) Download
✅ introspection: All 9 tests passed. Html Report (VSDrops) Download
✅ monotouch (macOS): All 12 tests passed. Html Report (VSDrops) Download
✅ monotouch (tvOS): All 15 tests passed. Html Report (VSDrops) Download
✅ msbuild: All 2 tests passed. Html Report (VSDrops) Download
✅ sharpie: All 1 tests passed. Html Report (VSDrops) Download
✅ xcframework: All 4 tests passed. Html Report (VSDrops) Download
✅ xtro: All 1 tests passed. Html Report (VSDrops) Download

macOS tests

✅ Tests on macOS Sonoma (14): All 5 tests passed. Html Report (VSDrops) Download

Pipeline on Agent
Hash: 4db2099e9f86576bca72ca495ce7f75af53c01bf [PR build]

[release/11.0.1xx-preview3] Make CoreCLR the default runtime for debu…

62775b4

…g builds.

rolfbjarne requested a review from Copilot March 31, 2026 14:33

Copilot started reviewing on behalf of rolfbjarne March 31, 2026 14:34 View session

Copilot AI reviewed Mar 31, 2026

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	<UseMonoRuntime Condition=" '$(UseMonoRuntime)' == '' And '$(_BundlerDebug)' == 'true'">false</UseMonoRuntime>
	<UseMonoRuntime Condition=" '$(UseMonoRuntime)' == '' And '$(Configuration)' == 'Debug'">false</UseMonoRuntime>

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rolfbjarne commented Mar 31, 2026

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vs-mobiletools-engineering-service2 commented Apr 2, 2026

✅ [CI Build #4db2099] Build passed (Build packages) ✅

Uh oh!

vs-mobiletools-engineering-service2 commented Apr 2, 2026

✅ [PR Build #4db2099] Build passed (Detect API changes) ✅

Uh oh!

vs-mobiletools-engineering-service2 commented Apr 2, 2026

✅ API diff for current PR / commit

✅ API diff vs stable

ℹ️ Generator diff

Uh oh!

vs-mobiletools-engineering-service2 commented Apr 2, 2026

✅ [CI Build #4db2099] Build passed (Build macOS tests) ✅

Uh oh!

vs-mobiletools-engineering-service2 commented Apr 2, 2026

🔥 [CI Build #4db2099] Test results 🔥

Test results

Failures

❌ dotnettests tests (iOS)

Failed tests

❌ dotnettests tests (MacCatalyst)

Failed tests

❌ dotnettests tests (tvOS)

Failed tests

❌ linker tests

Failed tests

❌ monotouch tests (iOS)

Failed tests

❌ monotouch tests (MacCatalyst)

Failed tests

❌ windows tests

Failed tests

❌ Tests on macOS Sequoia (15) tests

Failed tests

❌ Tests on macOS Tahoe (26) tests

Failed tests

Successes

macOS tests

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