From c2c5cb7420370f4f6123438cc18bc6ecfda5ca4e Mon Sep 17 00:00:00 2001
From: William Godbe <wigodbe@microsoft.com>
Date: Mon, 9 Feb 2026 09:53:14 -0800
Subject: [PATCH 1/6] Disable parallel restore for linker tests

---
 eng/testing/linker/project.csproj.template | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/eng/testing/linker/project.csproj.template b/eng/testing/linker/project.csproj.template
index 38688d6a95f2..86b8d5f599f1 100644
--- a/eng/testing/linker/project.csproj.template
+++ b/eng/testing/linker/project.csproj.template
@@ -15,6 +15,8 @@
     <InterceptorsPreviewNamespaces>$(InterceptorsPreviewNamespaces);Microsoft.AspNetCore.Http.Generated;Microsoft.Extensions.Validation.Generated</InterceptorsPreviewNamespaces>
     <!-- Ensure individual warnings are shown when publishing -->
     <TrimmerSingleWarn>false</TrimmerSingleWarn>
+    <!-- Should mitigate https://github.com/dotnet/dotnet/issues/4558 -->
+    <RestoreDisableParallel>true</RestoreDisableParallel>
     {AdditionalProperties}
   </PropertyGroup>
 

From a3507c7503cae59480e69210d8a1a9a5a318b5e9 Mon Sep 17 00:00:00 2001
From: William Godbe <wigodbe@microsoft.com>
Date: Mon, 9 Feb 2026 09:59:00 -0800
Subject: [PATCH 2/6] Disable parallel restore for trimming tests

---
 eng/testing/linker/trimmingTests.targets | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/eng/testing/linker/trimmingTests.targets b/eng/testing/linker/trimmingTests.targets
index 32235265135f..dd51c79d2150 100644
--- a/eng/testing/linker/trimmingTests.targets
+++ b/eng/testing/linker/trimmingTests.targets
@@ -104,7 +104,7 @@
     <MSBuild Projects="@(TestConsoleApps)"
              Targets="Restore"
              Condition="'$(SkipTrimmingProjectsRestore)' != 'true'"
-             Properties="MSBuildRestoreSessionId=$([System.Guid]::NewGuid());Configuration=$(Configuration)" />
+             Properties="MSBuildRestoreSessionId=$([System.Guid]::NewGuid());Configuration=$(Configuration);RestoreDisableParallel=true" />
 
     <MSBuild Projects="@(TestConsoleApps)"
              Targets="Publish"

From af3ee94e597366d8c92ea3eda82a06aa2ad77488 Mon Sep 17 00:00:00 2001
From: William Godbe <wigodbe@microsoft.com>
Date: Mon, 9 Feb 2026 09:59:42 -0800
Subject: [PATCH 3/6] Update comment to reference new GitHub issue

---
 eng/testing/linker/project.csproj.template | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/eng/testing/linker/project.csproj.template b/eng/testing/linker/project.csproj.template
index 86b8d5f599f1..5f6649089ba6 100644
--- a/eng/testing/linker/project.csproj.template
+++ b/eng/testing/linker/project.csproj.template
@@ -15,7 +15,7 @@
     <InterceptorsPreviewNamespaces>$(InterceptorsPreviewNamespaces);Microsoft.AspNetCore.Http.Generated;Microsoft.Extensions.Validation.Generated</InterceptorsPreviewNamespaces>
     <!-- Ensure individual warnings are shown when publishing -->
     <TrimmerSingleWarn>false</TrimmerSingleWarn>
-    <!-- Should mitigate https://github.com/dotnet/dotnet/issues/4558 -->
+    <!-- Should mitigate https://github.com/dotnet/aspnetcore/issues/61178 -->
     <RestoreDisableParallel>true</RestoreDisableParallel>
     {AdditionalProperties}
   </PropertyGroup>

From 6d3150ca1c6960bfbc927f5fd243ecc92501887a Mon Sep 17 00:00:00 2001
From: William Godbe <wigodbe@microsoft.com>
Date: Mon, 9 Feb 2026 11:49:34 -0800
Subject: [PATCH 4/6] Add property to disable parallel restore for trimming
 tests

Added a property group to disable parallel restore for trimming test projects to mitigate a specific issue.
---
 Directory.Build.props | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Directory.Build.props b/Directory.Build.props
index 6016e944f453..0df8e7ebe545 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -87,6 +87,11 @@
      <DisableLogTaskParameterItemMetadata_Csc_References>$(TrimTaskParameters)</DisableLogTaskParameterItemMetadata_Csc_References>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(IsTrimmingTestProject)' == 'true'">
+    <!-- Should mitigate https://github.com/dotnet/aspnetcore/issues/61178 -->
+    <RestoreDisableParallel>true</RestoreDisableParallel>
+  </PropertyGroup
+
   <Import Project="eng\QuarantinedTests.BeforeArcade.props" />
   <Import Project="Sdk.props" Sdk="Microsoft.DotNet.Arcade.Sdk" />
   <Import Project="eng\QuarantinedTests.AfterArcade.props" />

From 40d01a1dcb108f29c2b7e9ecb301e93b8dfc8b16 Mon Sep 17 00:00:00 2001
From: William Godbe <wigodbe@microsoft.com>
Date: Mon, 9 Feb 2026 11:52:43 -0800
Subject: [PATCH 5/6] Update PublishTrimmedProjects target for parallel build

---
 eng/testing/linker/trimmingTests.targets | 1 +
 1 file changed, 1 insertion(+)

diff --git a/eng/testing/linker/trimmingTests.targets b/eng/testing/linker/trimmingTests.targets
index dd51c79d2150..e6cdef66e9fa 100644
--- a/eng/testing/linker/trimmingTests.targets
+++ b/eng/testing/linker/trimmingTests.targets
@@ -102,6 +102,7 @@
           DependsOnTargets="GenerateProjects">
 
     <MSBuild Projects="@(TestConsoleApps)"
+             BuildInParallel="false"
              Targets="Restore"
              Condition="'$(SkipTrimmingProjectsRestore)' != 'true'"
              Properties="MSBuildRestoreSessionId=$([System.Guid]::NewGuid());Configuration=$(Configuration);RestoreDisableParallel=true" />

From 76642b8c6521253ba38ea15bf78d75cc83523fb1 Mon Sep 17 00:00:00 2001
From: William Godbe <wigodbe@microsoft.com>
Date: Mon, 9 Feb 2026 12:56:08 -0800
Subject: [PATCH 6/6] Fix PropertyGroup closing tag in Directory.Build.props

---
 Directory.Build.props | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Directory.Build.props b/Directory.Build.props
index 0df8e7ebe545..18641a0e7c73 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -90,7 +90,7 @@
   <PropertyGroup Condition="'$(IsTrimmingTestProject)' == 'true'">
     <!-- Should mitigate https://github.com/dotnet/aspnetcore/issues/61178 -->
     <RestoreDisableParallel>true</RestoreDisableParallel>
-  </PropertyGroup
+  </PropertyGroup>
 
   <Import Project="eng\QuarantinedTests.BeforeArcade.props" />
   <Import Project="Sdk.props" Sdk="Microsoft.DotNet.Arcade.Sdk" />