dotnet · dotnet-maestro · Dec 4, 2025 · Dec 5, 2025 · Dec 5, 2025 · Dec 5, 2025
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
@@ -23,7 +23,6 @@
   "remoteEnv": {
     "PATH": "${containerWorkspaceFolder}/.dotnet:${containerEnv:PATH}",
     "DOTNET_INSTALL_DIR": "${containerWorkspaceFolder}/.dotnet",
-    "DOTNET_MULTILEVEL_LOOKUP": "0",
     "DOTNET_ROOT": "${containerWorkspaceFolder}/.dotnet",
     "DOTNET_MSBUILD_SDK_RESOLVER_CLI_DIR": "${containerWorkspaceFolder}/.dotnet",
     "NUGET_PACKAGES": "/home/vscode/.nuget/packages"

diff --git a/build/RunTestsOnHelix.cmd b/build/RunTestsOnHelix.cmd
@@ -7,7 +7,6 @@ set NUGET_EXPERIMENTAL_NETWORK_RETRY_DELAY_MILLISECONDS=1000
 set MicrosoftNETBuildExtensionsTargets=%HELIX_CORRELATION_PAYLOAD%\ex\msbuildExtensions\Microsoft\Microsoft.NET.Build.Extensions\Microsoft.NET.Build.Extensions.targets
 set DOTNET_ROOT=%HELIX_CORRELATION_PAYLOAD%\d
 set PATH=%DOTNET_ROOT%;%PATH%
-set DOTNET_MULTILEVEL_LOOKUP=0
 set TestFullMSBuild=%1
 
 REM Ensure Visual Studio instances allow preview SDKs

diff --git a/eng/SignCheckExclusionsFile.txt b/eng/SignCheckExclusionsFile.txt
diff --git a/eng/Signing.props b/eng/Signing.props
@@ -86,6 +86,9 @@
   <ItemGroup>
     <!-- Roslyn apphosts -->
     <FileSignInfo Condition="'$(TargetOS)' == 'osx'" Include="csc;vbc;VBCSCompiler" CertificateName="MacDeveloperHarden" />
+
+    <!-- Roslyn apphosts -->
+    <FileSignInfo Condition="'$(TargetOS)' == 'osx'" Include="csc;vbc;VBCSCompiler" CertificateName="MacDeveloperHarden" />
   </ItemGroup>
 
   <!-- Filter out any test packages from ItemsToSign -->

diff --git a/eng/Version.Details.props b/eng/Version.Details.props
diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
diff --git a/eng/Versions.props b/eng/Versions.props
@@ -1,36 +1,33 @@
 <Project DefaultTargets="Build">
-  <Import Project="Version.Details.props" Condition="Exists('Version.Details.props')" />
-  <PropertyGroup>
-    <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
-  </PropertyGroup>
+
+  <Import Project="Version.Details.props" />
+
   <PropertyGroup Label="Repo version information">
     <VersionMajor>11</VersionMajor>
     <VersionMinor>0</VersionMinor>
     <VersionSDKMinor>1</VersionSDKMinor>
     <VersionFeature>00</VersionFeature>
+    <VersionPrefix>$(VersionMajor).$(VersionMinor).$(VersionSDKMinor)$(VersionFeature)</VersionPrefix>
+    <PreReleaseVersionLabel>alpha</PreReleaseVersionLabel>
+    <PreReleaseVersionIteration>1</PreReleaseVersionIteration>
+    <!-- Allowed values: '', 'prerelease', 'release'. Set to 'release' when stabilizing. -->
+    <DotNetFinalVersionKind></DotNetFinalVersionKind>
+
     <!-- This property powers the SdkAnalysisLevel property in end-user MSBuild code.
          It should always be the hundreds-value of the current SDK version, never any
          preview version components or anything else. E.g. 8.0.100, 9.0.300, etc. -->
     <SdkFeatureBand>$(VersionMajor).$(VersionMinor).$(VersionSDKMinor)00</SdkFeatureBand>
     <BuiltinWorkloadFeatureBand>$(VersionMajor).$(VersionMinor).100</BuiltinWorkloadFeatureBand>
-    <VersionPrefix>$(VersionMajor).$(VersionMinor).$(VersionSDKMinor)$(VersionFeature)</VersionPrefix>
     <PreviousVersionPrefix>10.0.100</PreviousVersionPrefix>
     <MajorMinorVersion>$(VersionMajor).$(VersionMinor)</MajorMinorVersion>
     <CliProductBandVersion>$(MajorMinorVersion).$(VersionSDKMinor)</CliProductBandVersion>
-    <!-- Enable to remove prerelease label. -->
-    <StabilizePackageVersion Condition="'$(StabilizePackageVersion)' == ''">false</StabilizePackageVersion>
-    <DotNetFinalVersionKind Condition="'$(StabilizePackageVersion)' == 'true'">release</DotNetFinalVersionKind>
-    <!-- Calculate prerelease label -->
-    <PreReleaseVersionLabel Condition="'$(StabilizePackageVersion)' != 'true'">alpha</PreReleaseVersionLabel>
-    <PreReleaseVersionLabel Condition="'$(StabilizePackageVersion)' == 'true' and $(VersionPrefix.EndsWith('00'))">rtm</PreReleaseVersionLabel>
-    <PreReleaseVersionLabel Condition="'$(StabilizePackageVersion)' == 'true' and !$(VersionPrefix.EndsWith('00'))">servicing</PreReleaseVersionLabel>
-    <PreReleaseVersionIteration Condition="'$(StabilizePackageVersion)' != 'true'">0</PreReleaseVersionIteration>
+
     <!-- In source-build the version of the compiler must be same or newer than the version of the
          compiler API targeted by analyzer assemblies. This is mostly an issue on source-build as
          in that build mode analyzer assemblies always target the live compiler API. -->
     <UsingToolMicrosoftNetCompilers Condition="'$(DotNetBuildSourceOnly)' == 'true'">true</UsingToolMicrosoftNetCompilers>
-    <FlagNetStandard1XDependencies Condition="'$(DotNetBuildSourceOnly)' == 'true'">true</FlagNetStandard1XDependencies>
   </PropertyGroup>
+
   <PropertyGroup Label="Servicing version information">
     <VersionFeature21>30</VersionFeature21>
     <VersionFeature31>32</VersionFeature31>
@@ -47,11 +44,13 @@
     <VersionFeature80ForWorkloads>$(VersionFeature80)</VersionFeature80ForWorkloads>
     <VersionFeature90ForWorkloads>$(VersionFeature90)</VersionFeature90ForWorkloads>
   </PropertyGroup>
+
   <PropertyGroup Label="Restore feeds">
     <!-- In an orchestrated build, this may be overridden to other Azure feeds. -->
     <DotNetAssetRootUrl Condition="'$(DotNetAssetRootUrl)'==''">https://ci.dot.net/public/</DotNetAssetRootUrl>
     <DotNetPrivateAssetRootUrl Condition="'$(DotNetPrivateAssetRootUrl)'==''">https://dotnetclimsrc.blob.core.windows.net/dotnet/</DotNetPrivateAssetRootUrl>
   </PropertyGroup>
+
   <PropertyGroup Label="Production dependencies">
     <MicrosoftCssParserVersion>1.0.0-20230414.1</MicrosoftCssParserVersion>
     <MicrosoftApplicationInsightsPackageVersion>2.23.0</MicrosoftApplicationInsightsPackageVersion>
@@ -69,13 +68,16 @@
     <!-- When updating MicrosoftVisualStudioSolutionPersistenceVersion make sure to sync with dotnet/msbuild, dotnet/source-build-externals and NuGet/NuGet.Client -->
     <MicrosoftVisualStudioSolutionPersistenceVersion>1.0.52</MicrosoftVisualStudioSolutionPersistenceVersion>
   </PropertyGroup>
+
   <PropertyGroup Label="MicroBuild.Core version">
     <MicroBuildCorePackageVersion>0.2.0</MicroBuildCorePackageVersion>
   </PropertyGroup>
+
   <PropertyGroup>
     <!-- Dependency from https://github.com/dotnet/aspire -->
     <AspirePackageVersion>9.4.0</AspirePackageVersion>
   </PropertyGroup>
+
   <PropertyGroup>
     <!-- These are minimum versions used for netfx-targeted components that run in Visual Studio because in those cases,
          Visual Studio is providing those assemblies, and we should work with whichever version it ships. -->
@@ -93,6 +95,7 @@
     <SystemThreadingTasksExtensionsToolsetPackageVersion>4.5.4</SystemThreadingTasksExtensionsToolsetPackageVersion>
     <SystemResourcesExtensionsToolsetPackageVersion>8.0.0</SystemResourcesExtensionsToolsetPackageVersion>
   </PropertyGroup>
+
   <PropertyGroup>
     <!-- Dependencies from https://github.com/Microsoft/msbuild -->
     <!-- In VMR modes, MicrosoftBuildVersion and MicrosoftBuildLocalizationVersion will end
@@ -115,6 +118,7 @@
     <MicrosoftBuildMinimumVersion Condition="'$(DotNetBuildSourceOnly)' != 'true'">17.14.28</MicrosoftBuildMinimumVersion>
     <MinimumVSVersion>18.0</MinimumVSVersion>
   </PropertyGroup>
+
   <PropertyGroup>
     <!-- Dependencies from https://github.com/dotnet/emsdk -->
     <!-- emscripten versions, these are are included in package IDs and need to be kept in sync with emsdk -->
@@ -124,15 +128,13 @@
     <EmscriptenVersionNet7>3.1.12</EmscriptenVersionNet7>
     <EmscriptenVersionNet6>2.0.23</EmscriptenVersionNet6>
   </PropertyGroup>
+
   <PropertyGroup Label="Manually updated">
     <!-- Dependencies from https://github.com/microsoft/MSBuildLocator -->
     <MicrosoftBuildLocatorPackageVersion>1.10.2</MicrosoftBuildLocatorPackageVersion>
     <MicrosoftCodeAnalysisCSharpAnalyzerPinnedVersionPackageVersion>4.0.1</MicrosoftCodeAnalysisCSharpAnalyzerPinnedVersionPackageVersion>
   </PropertyGroup>
-  <!-- Get .NET Framework reference assemblies from NuGet packages -->
-  <PropertyGroup>
-    <UsingToolNetFrameworkReferenceAssemblies>true</UsingToolNetFrameworkReferenceAssemblies>
-  </PropertyGroup>
+
   <!-- Test Dependencies -->
   <PropertyGroup>
     <AwesomeAssertionsVersion>8.0.2</AwesomeAssertionsVersion>
@@ -142,6 +144,7 @@
     <MicrosoftDotNetInstallerWindowsSecurityTestDataPackageVersion>8.0.0-beta.23607.1</MicrosoftDotNetInstallerWindowsSecurityTestDataPackageVersion>
     <BenchmarkDotNetPackageVersion>0.14.0</BenchmarkDotNetPackageVersion>
   </PropertyGroup>
+
   <PropertyGroup Label="Workload manifest package versions">
     <MauiFeatureBand>10.0.100</MauiFeatureBand>
     <MauiWorkloadManifestVersion>10.0.0</MauiWorkloadManifestVersion>
@@ -151,9 +154,12 @@
     <XamarinMacOSWorkloadManifestVersion>26.0.11017</XamarinMacOSWorkloadManifestVersion>
     <XamarinTvOSWorkloadManifestVersion>26.0.11017</XamarinTvOSWorkloadManifestVersion>
   </PropertyGroup>
+
   <PropertyGroup Label="Pinned dependency">
     <!-- This package is not being produced outside of the 2.0 branch of corefx and should not change. -->
     <CLI_NETStandardLibraryNETFrameworkVersion>2.0.1-servicing-26011-01</CLI_NETStandardLibraryNETFrameworkVersion>
   </PropertyGroup>
+
   <Import Project="ManualVersions.props" />
+
 </Project>
diff --git a/eng/common/core-templates/job/publish-build-assets.yml b/eng/common/core-templates/job/publish-build-assets.yml
@@ -122,8 +122,9 @@ jobs:
 
     # Populate internal runtime variables.
     - template: /eng/common/templates/steps/enable-internal-sources.yml
-      parameters:
-        legacyCredential: $(dn-bot-dnceng-artifact-feeds-rw)
+      ${{ if eq(variables['System.TeamProject'], 'DevDiv') }}:
+        parameters:
+            legacyCredential: $(dn-bot-dnceng-artifact-feeds-rw)
 
     - template: /eng/common/templates/steps/enable-internal-runtimes.yml
 
@@ -140,7 +141,7 @@ jobs:
           /p:MaestroApiEndpoint=https://maestro.dot.net
           /p:OfficialBuildId=$(OfficialBuildId)
           -runtimeSourceFeed https://ci.dot.net/internal
-          -runtimeSourceFeedKey $(dotnetbuilds-internal-container-read-token-base64)
+          -runtimeSourceFeedKey '$(dotnetbuilds-internal-container-read-token-base64)'
 
       condition: ${{ parameters.condition }}
       continueOnError: ${{ parameters.continueOnError }}
@@ -189,6 +190,11 @@ jobs:
           BARBuildId: ${{ parameters.BARBuildId }}
           PromoteToChannelIds: ${{ parameters.PromoteToChannelIds }}
           is1ESPipeline: ${{ parameters.is1ESPipeline }}
+
+      # Darc is targeting 8.0, so make sure it's installed
+      - task: UseDotNet@2
+        inputs:
+          version: 8.0.x
 
       - task: AzureCLI@2
         displayName: Publish Using Darc
@@ -205,8 +211,8 @@ jobs:
             -ArtifactsPublishingAdditionalParameters '${{ parameters.artifactsPublishingAdditionalParameters }}'
             -SymbolPublishingAdditionalParameters '${{ parameters.symbolPublishingAdditionalParameters }}'
             -SkipAssetsPublishing '${{ parameters.isAssetlessBuild }}'
-            -runtimeSourceFeed https://ci.dot.net/internal 
-            -runtimeSourceFeedKey $(dotnetbuilds-internal-container-read-token-base64)
+            -runtimeSourceFeed https://ci.dot.net/internal
+            -runtimeSourceFeedKey '$(dotnetbuilds-internal-container-read-token-base64)'
 
     - ${{ if eq(parameters.enablePublishBuildArtifacts, 'true') }}:
       - template: /eng/common/core-templates/steps/publish-logs.yml

diff --git a/eng/common/core-templates/job/source-build.yml b/eng/common/core-templates/job/source-build.yml
@@ -60,10 +60,10 @@ jobs:
       pool:
         ${{ if eq(variables['System.TeamProject'], 'public') }}:
           name: $[replace(replace(eq(contains(coalesce(variables['System.PullRequest.TargetBranch'], variables['Build.SourceBranch'], 'refs/heads/main'), 'release'), 'true'), True, 'NetCore-Svc-Public' ), False, 'NetCore-Public')]
-          demands: ImageOverride -equals build.ubuntu.2004.amd64
+          demands: ImageOverride -equals build.ubuntu.2204.amd64
         ${{ if eq(variables['System.TeamProject'], 'internal') }}:
           name: $[replace(replace(eq(contains(coalesce(variables['System.PullRequest.TargetBranch'], variables['Build.SourceBranch'], 'refs/heads/main'), 'release'), 'true'), True, 'NetCore1ESPool-Svc-Internal'), False, 'NetCore1ESPool-Internal')]
-          image: 1es-mariner-2
+          image: 1es-azurelinux-3
           os: linux
     ${{ else }}:
       pool:

diff --git a/eng/common/core-templates/job/source-index-stage1.yml b/eng/common/core-templates/job/source-index-stage1.yml
@@ -25,10 +25,10 @@ jobs:
     pool:
       ${{ if eq(variables['System.TeamProject'], 'public') }}:
         name: $(DncEngPublicBuildPool)
-        image: windows.vs2022.amd64.open
+        image: windows.vs2026preview.scout.amd64.open
       ${{ if eq(variables['System.TeamProject'], 'internal') }}:
         name: $(DncEngInternalBuildPool)
-        image: windows.vs2022.amd64
+        image: windows.vs2026preview.scout.amd64
 
   steps:
   - ${{ if eq(parameters.is1ESPipeline, '') }}:

diff --git a/eng/common/core-templates/post-build/post-build.yml b/eng/common/core-templates/post-build/post-build.yml
@@ -127,11 +127,11 @@ stages:
         ${{ else }}:
           ${{ if eq(parameters.is1ESPipeline, true) }}:
             name: $(DncEngInternalBuildPool)
-            image: windows.vs2022.amd64
+            image: windows.vs2026preview.scout.amd64
             os: windows
           ${{ else }}:
             name: $(DncEngInternalBuildPool)
-            demands: ImageOverride -equals windows.vs2022.amd64
+            demands: ImageOverride -equals windows.vs2026preview.scout.amd64
 
       steps:
       - template: /eng/common/core-templates/post-build/setup-maestro-vars.yml
@@ -175,7 +175,7 @@ stages:
             os: windows
           ${{ else }}:
             name: $(DncEngInternalBuildPool)
-            demands: ImageOverride -equals windows.vs2022.amd64
+            demands: ImageOverride -equals windows.vs2026preview.scout.amd64
       steps:
       - template: /eng/common/core-templates/post-build/setup-maestro-vars.yml
         parameters:
@@ -236,7 +236,7 @@ stages:
             os: windows
           ${{ else }}:
             name: $(DncEngInternalBuildPool)
-            demands: ImageOverride -equals windows.vs2022.amd64
+            demands: ImageOverride -equals windows.vs2026preview.scout.amd64
       steps:
       - template: /eng/common/core-templates/post-build/setup-maestro-vars.yml
         parameters:
@@ -305,14 +305,19 @@ stages:
           PromoteToChannelIds: ${{ parameters.PromoteToChannelIds }}
           is1ESPipeline: ${{ parameters.is1ESPipeline }}
 
-      - task: NuGetAuthenticate@1 # Populate internal runtime variables.
+      - task: NuGetAuthenticate@1
 
+      # Populate internal runtime variables.
       - template: /eng/common/templates/steps/enable-internal-sources.yml
         parameters:
           legacyCredential: $(dn-bot-dnceng-artifact-feeds-rw)
 
       - template: /eng/common/templates/steps/enable-internal-runtimes.yml
 
+      - task: UseDotNet@2
+        inputs:
+          version: 8.0.x
+
       - task: AzureCLI@2
         displayName: Publish Using Darc
         inputs:
@@ -330,4 +335,4 @@ stages:
               -SymbolPublishingAdditionalParameters '${{ parameters.symbolPublishingAdditionalParameters }}'
               -SkipAssetsPublishing '${{ parameters.isAssetlessBuild }}'
               -runtimeSourceFeed https://ci.dot.net/internal 
-              -runtimeSourceFeedKey $(dotnetbuilds-internal-container-read-token-base64)
+              -runtimeSourceFeedKey '$(dotnetbuilds-internal-container-read-token-base64)'
diff --git a/eng/common/core-templates/steps/install-microbuild.yml b/eng/common/core-templates/steps/install-microbuild.yml
@@ -13,6 +13,8 @@ parameters:
   # Unfortunately, _SignType can't be used to exclude the use of the service connection in non-real sign scenarios. The
   # variable is not available in template expression. _SignType has a very large proliferation across .NET, so replacing it is tough.
   microbuildUseESRP: true
+  # Microbuild installation directory
+  microBuildOutputFolder: $(Agent.TempDirectory)/MicroBuild
   # Microbuild version
   microbuildPluginVersion: 'latest'
 
@@ -27,8 +29,27 @@ steps:
         inputs:
           packageType: sdk
           version: 8.0.x
-          installationPath: ${{ parameters.microBuildOutputFolder }}/.dotnet
-          workingDirectory: ${{ parameters.microBuildOutputFolder }}
+          installationPath: ${{ parameters.microBuildOutputFolder }}/.dotnet-microbuild
+        condition: and(succeeded(), ne(variables['Agent.Os'], 'Windows_NT'))
+
+      - script: |
+          set -euo pipefail
+
+          # UseDotNet@2 prepends the dotnet executable path to the PATH variable, so we can call dotnet directly
+          version=$(dotnet --version)
+          cat << 'EOF' > ${{ parameters.microBuildOutputFolder }}/global.json
+          {
+            "sdk": {
+              "version": "$version",
+              "paths": [
+                "${{ parameters.microBuildOutputFolder }}/.dotnet-microbuild"
+              ],
+              "errorMessage": "The .NET SDK version $version is required to install the MicroBuild signing plugin."
+            }
+          }
+          EOF
+        displayName: 'Add global.json to MicroBuild Installation path'
+        workingDirectory: ${{ parameters.microBuildOutputFolder }}
         condition: and(succeeded(), ne(variables['Agent.Os'], 'Windows_NT'))
 
     - script: |
@@ -68,7 +89,7 @@ steps:
               ConnectedPMEServiceName: 248d384a-b39b-46e3-8ad5-c2c210d5e7ca
         microbuildEnv:
           TeamName: $(_TeamName)
-          MicroBuildOutputFolderOverride: $(Agent.TempDirectory)/MicroBuild
+          MicroBuildOutputFolderOverride: ${{ parameters.microBuildOutputFolder }}
           SYSTEM_ACCESSTOKEN: $(System.AccessToken)
         continueOnError: ${{ parameters.continueOnError }}
         condition: and(succeeded(), eq(variables['Agent.Os'], 'Windows_NT'), in(variables['_SignType'], 'real', 'test'))
@@ -82,6 +103,7 @@ steps:
             zipSources: false
             feedSource: https://dnceng.pkgs.visualstudio.com/_packaging/MicroBuildToolset/nuget/v3/index.json
             version: ${{ parameters.microbuildPluginVersion }}
+            workingDirectory: ${{ parameters.microBuildOutputFolder }}
             ${{ if eq(parameters.microbuildUseESRP, true) }}:
               ConnectedServiceName: 'MicroBuild Signing Task (DevDiv)'
               ${{ if eq(variables['System.TeamProject'], 'DevDiv') }}:
@@ -90,7 +112,7 @@ steps:
                 ConnectedPMEServiceName: c24de2a5-cc7a-493d-95e4-8e5ff5cad2bc
           microbuildEnv:
             TeamName: $(_TeamName)
-            MicroBuildOutputFolderOverride: $(Agent.TempDirectory)/MicroBuild
+            MicroBuildOutputFolderOverride: ${{ parameters.microBuildOutputFolder }}
             SYSTEM_ACCESSTOKEN: $(System.AccessToken)
           continueOnError: ${{ parameters.continueOnError }}
           condition: and(succeeded(), ne(variables['Agent.Os'], 'Windows_NT'),  eq(variables['_SignType'], 'real'))
diff --git a/eng/common/generate-sbom-prep.sh b/eng/common/generate-sbom-prep.sh
diff --git a/eng/common/sdk-task.ps1 b/eng/common/sdk-task.ps1
@@ -70,7 +70,7 @@ try {
       $GlobalJson.tools | Add-Member -Name "vs" -Value (ConvertFrom-Json "{ `"version`": `"16.5`" }") -MemberType NoteProperty
     }
     if( -not ($GlobalJson.tools.PSObject.Properties.Name -match "xcopy-msbuild" )) {
-      $GlobalJson.tools | Add-Member -Name "xcopy-msbuild" -Value "17.14.16" -MemberType NoteProperty
+      $GlobalJson.tools | Add-Member -Name "xcopy-msbuild" -Value "18.0.0" -MemberType NoteProperty
     }
     if ($GlobalJson.tools."xcopy-msbuild".Trim() -ine "none") {
         $xcopyMSBuildToolsFolder = InitializeXCopyMSBuild $GlobalJson.tools."xcopy-msbuild" -install $true