Exclude satellite assemblies from _PostTrimmingPipeline

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.TypeMap.LlvmIr.targets

@@ -248,7 +248,7 @@
  AfterTargets="ILLink"
  Condition=" '$(PublishTrimmed)' == 'true' ">
  <ItemGroup>
- <_PostTrimmingAssembly Include="@(ResolvedFileToPublish)" Condition=" '%(Extension)' == '.dll' " />
+ <_PostTrimmingAssembly Include="@(ResolvedFileToPublish)" Condition=" '%(Extension)' == '.dll' and '%(ResolvedFileToPublish.PostprocessAssembly)' == 'true' " />
  </ItemGroup>
  <PostTrimmingPipeline
  Assemblies="@(_PostTrimmingAssembly)"

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/PackagingTest.cs

@@ -726,6 +726,88 @@ public void MissingSatelliteAssemblyInApp ([Values] bool publishAot, [Values] An
  }
  }
 
+ /// <summary>
+ /// Verifies that _PostTrimmingPipeline does not include satellite assemblies
+ /// (.resources.dll) in its input. Satellite assemblies are not processed by
+ /// ILLink and retain their original paths in the shared NuGet package cache.
+ /// Including them causes PostTrimmingPipeline to open them with ReadWrite
+ /// access, leading to IOException in parallel multi-RID builds.
+ /// See: https://github.com/dotnet/android/issues/11085
+ /// </summary>
+ [Test]
+ [NonParallelizable] // Commonly fails NuGet restore
+ public void PostTrimmingPipelineExcludesSatelliteAssemblies ()
+ {
+ var proj = new XamarinAndroidApplicationProject {
+ IsRelease = true,
+ };
+ proj.SetRuntime (AndroidRuntime.MonoVM);
+ proj.SetRuntimeIdentifiers (AndroidTargetArch.Arm64);
+ proj.PackageReferences.Add (new Package {
+ Id = "Humanizer.Core",
+ Version = "2.14.1",
+ });
+ proj.PackageReferences.Add (new Package {
+ Id = "Humanizer.Core.es",
+ Version = "2.14.1",
+ });
+ proj.MainActivity = proj.DefaultMainActivity
+ .Replace ("//${USINGS}", @"using Humanizer;
+using System.Globalization;")
+ .Replace ("//${AFTER_ONCREATE}", @"var c = new CultureInfo (""es-ES"");
+Console.WriteLine ($""{DateTime.UtcNow.AddHours(-30).Humanize(culture:c)}"");");
+ proj.OtherBuildItems.Add (new BuildItem ("Using", "System.Globalization"));
+ proj.OtherBuildItems.Add (new BuildItem ("Using", "Humanizer"));
+
+ // Inject a diagnostic target that logs the _PostTrimmingAssembly items
+ // created by the production _PostTrimmingPipeline target. In MSBuild,
+ // items defined in a target's <ItemGroup> are visible to subsequent targets.
+ proj.Imports.Add (new Import ("PostTrimmingDiag.targets") {
+ TextContent = () => """
+ <Project>
+ <Target Name="_DiagLogPostTrimmingAssemblies"
+ AfterTargets="_PostTrimmingPipeline"
+ Condition=" '$(PublishTrimmed)' == 'true' ">
+ <Message Importance="high" Text="DIAG_PTA: %(_PostTrimmingAssembly.Identity)" />
+ <Message Importance="high" Text="DIAG_RFP: %(ResolvedFileToPublish.Identity)"
+ Condition=" '%(ResolvedFileToPublish.Extension)' == '.dll' and '%(Filename)' != '' and $([System.String]::Copy('%(Filename)').EndsWith('.resources')) " />
+ </Target>
+ </Project>
+ """,
+ });
+
+ using var b = CreateApkBuilder ();
+ Assert.IsTrue (b.Build (proj), "Build should have succeeded.");
+
+ // Verify the diagnostic target actually ran and logged assemblies
+ Assert.IsTrue (
+ b.LastBuildOutput.ContainsText ("DIAG_PTA:"),
+ "Diagnostic target should have logged _PostTrimmingAssembly items");
+
+ // Verify satellite assemblies ARE present in ResolvedFileToPublish (positive check)
+ bool hasSatelliteInRfp = false;
+ foreach (var line in b.LastBuildOutput) {
+ if (line.Contains ("DIAG_RFP:") && line.Contains (".resources.dll")) {
+ hasSatelliteInRfp = true;
+ break;
+ }
+ }
+ Assert.IsTrue (hasSatelliteInRfp,
+ "Satellite assemblies should be present in ResolvedFileToPublish to confirm the scenario is exercised");
+
+ // Verify satellite assemblies were NOT included in _PostTrimmingAssembly
+ var satelliteLines = new List<string> ();
+ foreach (var line in b.LastBuildOutput) {
+ if (line.Contains ("DIAG_PTA:") && line.Contains (".resources.dll")) {
+ satelliteLines.Add (line.Trim ());
+ }
+ }
+ Assert.IsEmpty (satelliteLines,
+ "Satellite assemblies (.resources.dll) should not be passed to PostTrimmingPipeline. " +
+ "They retain paths in the shared NuGet cache and cause file locking conflicts in parallel RID builds. Found:\n" +
+ string.Join ("\n", satelliteLines));
+ }
+
  [Test]
  public void IgnoreManifestFromJar ([Values] AndroidRuntime runtime)
  {