diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index ed61aa03262..db7d7411312 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -96,14 +96,14 @@
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
       <Sha>3a25a7f1cc446b60678ed25c9d829420d6321eba</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="9.0.0-beta.25161.4">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="9.0.0-beta.25415.3">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>f33d9e642f0e68a61312164cd9e0baf4e142a999</Sha>
+      <Sha>d87d66c43d0660e5c8e84e667c5c8a8140bce888</Sha>
     </Dependency>
     <!-- Intermediate is necessary for source build. -->
-    <Dependency Name="Microsoft.SourceBuild.Intermediate.arcade" Version="9.0.0-beta.25161.4">
+    <Dependency Name="Microsoft.SourceBuild.Intermediate.arcade" Version="9.0.0-beta.25415.3">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>f33d9e642f0e68a61312164cd9e0baf4e142a999</Sha>
+      <Sha>d87d66c43d0660e5c8e84e667c5c8a8140bce888</Sha>
       <SourceBuild RepoName="arcade" ManagedOnly="true" />
     </Dependency>
     <!-- Necessary for source-build. This allows Microsoft.Extensions.ObjectPool and System.Collections.Immutable packages
diff --git a/eng/Versions.props b/eng/Versions.props
index 11347c0bf28..7bbdb565dca 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -50,7 +50,7 @@
     <MicrosoftNETCoreBrowserDebugHostTransportPackageVersion>6.0.2-servicing.22064.6</MicrosoftNETCoreBrowserDebugHostTransportPackageVersion>
     <MicrosoftNETCorePlatformsPackageVersion>6.0.1</MicrosoftNETCorePlatformsPackageVersion>
     <MicrosoftSourceBuildIntermediatesourcebuildreferencepackagesPackageVersion>10.0.617601</MicrosoftSourceBuildIntermediatesourcebuildreferencepackagesPackageVersion>
-    <MicrosoftSourceBuildIntermediatearcadePackageVersion>9.0.0-beta.25161.4</MicrosoftSourceBuildIntermediatearcadePackageVersion>
+    <MicrosoftSourceBuildIntermediatearcadePackageVersion>9.0.0-beta.25415.3</MicrosoftSourceBuildIntermediatearcadePackageVersion>
     <MicrosoftNetCompilersToolsetPackageVersion>4.14.0-3.25176.5</MicrosoftNetCompilersToolsetPackageVersion>
     <MicrosoftCommonLanguageServerProtocolFrameworkPackageVersion>4.14.0-3.25176.5</MicrosoftCommonLanguageServerProtocolFrameworkPackageVersion>
     <MicrosoftCodeAnalysisExternalAccessRazorPackageVersion>4.14.0-3.25176.5</MicrosoftCodeAnalysisExternalAccessRazorPackageVersion>
diff --git a/eng/common/SetupNugetSources.ps1 b/eng/common/SetupNugetSources.ps1
index 5db4ad71ee2..792b60b49d4 100644
--- a/eng/common/SetupNugetSources.ps1
+++ b/eng/common/SetupNugetSources.ps1
@@ -10,8 +10,8 @@
 #    displayName: Setup Private Feeds Credentials
 #    condition: eq(variables['Agent.OS'], 'Windows_NT')
 #    inputs:
-#      filePath: $(Build.SourcesDirectory)/eng/common/SetupNugetSources.ps1
-#      arguments: -ConfigFile $(Build.SourcesDirectory)/NuGet.config -Password $Env:Token
+#      filePath: $(System.DefaultWorkingDirectory)/eng/common/SetupNugetSources.ps1
+#      arguments: -ConfigFile $(System.DefaultWorkingDirectory)/NuGet.config -Password $Env:Token
 #    env:
 #      Token: $(dn-bot-dnceng-artifact-feeds-rw)
 #
diff --git a/eng/common/SetupNugetSources.sh b/eng/common/SetupNugetSources.sh
index 4604b61b032..facb415ca6f 100644
--- a/eng/common/SetupNugetSources.sh
+++ b/eng/common/SetupNugetSources.sh
@@ -11,8 +11,8 @@
 #  - task: Bash@3
 #    displayName: Setup Internal Feeds
 #    inputs:
-#      filePath: $(Build.SourcesDirectory)/eng/common/SetupNugetSources.sh
-#      arguments: $(Build.SourcesDirectory)/NuGet.config
+#      filePath: $(System.DefaultWorkingDirectory)/eng/common/SetupNugetSources.sh
+#      arguments: $(System.DefaultWorkingDirectory)/NuGet.config
 #    condition: ne(variables['Agent.OS'], 'Windows_NT')
 #  - task: NuGetAuthenticate@1
 #
diff --git a/eng/common/core-templates/job/job.yml b/eng/common/core-templates/job/job.yml
index ba53ebfbd51..8da43d3b583 100644
--- a/eng/common/core-templates/job/job.yml
+++ b/eng/common/core-templates/job/job.yml
@@ -19,6 +19,7 @@ parameters:
   # publishing defaults
   artifacts: ''
   enableMicrobuild: false
+  microbuildUseESRP: true
   enablePublishBuildArtifacts: false
   enablePublishBuildAssets: false
   enablePublishTestResults: false
@@ -134,6 +135,11 @@ jobs:
           signType: $(_SignType)
           zipSources: false
           feedSource: https://dnceng.pkgs.visualstudio.com/_packaging/MicroBuildToolset/nuget/v3/index.json
+          ${{ if eq(parameters.microbuildUseESRP, true) }}:
+            ${{ if eq(variables['System.TeamProject'], 'DevDiv') }}:
+              ConnectedPMEServiceName: 6cc74545-d7b9-4050-9dfa-ebefcc8961ea
+            ${{ else }}:
+              ConnectedPMEServiceName: 248d384a-b39b-46e3-8ad5-c2c210d5e7ca
         env:
           TeamName: $(_TeamName)
           MicroBuildOutputFolderOverride: '$(Agent.TempDirectory)'
@@ -160,7 +166,7 @@ jobs:
       inputs:
         languages: ${{ coalesce(parameters.richCodeNavigationLanguage, 'csharp') }}
         environment: ${{ coalesce(parameters.richCodeNavigationEnvironment, 'internal') }}
-        richNavLogOutputDirectory: $(Build.SourcesDirectory)/artifacts/bin
+        richNavLogOutputDirectory: $(System.DefaultWorkingDirectory)/artifacts/bin
         uploadRichNavArtifacts: ${{ coalesce(parameters.richCodeNavigationUploadArtifacts, false) }}
       continueOnError: true
 
@@ -183,7 +189,7 @@ jobs:
       inputs:
         testResultsFormat: 'xUnit'
         testResultsFiles: '*.xml'
-        searchFolder: '$(Build.SourcesDirectory)/artifacts/TestResults/$(_BuildConfig)'
+        searchFolder: '$(System.DefaultWorkingDirectory)/artifacts/TestResults/$(_BuildConfig)'
         testRunTitle: ${{ coalesce(parameters.testRunTitle, parameters.name, '$(System.JobName)') }}-xunit
         mergeTestResults: ${{ parameters.mergeTestResults }}
       continueOnError: true
@@ -194,7 +200,7 @@ jobs:
       inputs:
         testResultsFormat: 'VSTest'
         testResultsFiles: '*.trx'
-        searchFolder: '$(Build.SourcesDirectory)/artifacts/TestResults/$(_BuildConfig)'
+        searchFolder: '$(System.DefaultWorkingDirectory)/artifacts/TestResults/$(_BuildConfig)'
         testRunTitle: ${{ coalesce(parameters.testRunTitle, parameters.name, '$(System.JobName)') }}-trx
         mergeTestResults: ${{ parameters.mergeTestResults }}
       continueOnError: true
@@ -238,7 +244,7 @@ jobs:
     - task: CopyFiles@2
       displayName: Gather buildconfiguration for build retry
       inputs:
-        SourceFolder: '$(Build.SourcesDirectory)/eng/common/BuildConfiguration'
+        SourceFolder: '$(System.DefaultWorkingDirectory)/eng/common/BuildConfiguration'
         Contents: '**'
         TargetFolder: '$(Build.ArtifactStagingDirectory)/eng/common/BuildConfiguration'
       continueOnError: true
diff --git a/eng/common/core-templates/job/onelocbuild.yml b/eng/common/core-templates/job/onelocbuild.yml
index 00feec8ebbc..edefa789d36 100644
--- a/eng/common/core-templates/job/onelocbuild.yml
+++ b/eng/common/core-templates/job/onelocbuild.yml
@@ -8,7 +8,7 @@ parameters:
   CeapexPat: $(dn-bot-ceapex-package-r) # PAT for the loc AzDO instance https://dev.azure.com/ceapex
   GithubPat: $(BotAccount-dotnet-bot-repo-PAT)
 
-  SourcesDirectory: $(Build.SourcesDirectory)
+  SourcesDirectory: $(System.DefaultWorkingDirectory)
   CreatePr: true
   AutoCompletePr: false
   ReusePr: true
@@ -68,7 +68,7 @@ jobs:
     - ${{ if ne(parameters.SkipLocProjectJsonGeneration, 'true') }}:
       - task: Powershell@2
         inputs:
-          filePath: $(Build.SourcesDirectory)/eng/common/generate-locproject.ps1
+          filePath: $(System.DefaultWorkingDirectory)/eng/common/generate-locproject.ps1
           arguments: $(_GenerateLocProjectArguments)
         displayName: Generate LocProject.json
         condition: ${{ parameters.condition }}
@@ -115,7 +115,7 @@ jobs:
         is1ESPipeline: ${{ parameters.is1ESPipeline }}
         args:
           displayName: Publish LocProject.json
-          pathToPublish: '$(Build.SourcesDirectory)/eng/Localize/'
+          pathToPublish: '$(System.DefaultWorkingDirectory)/eng/Localize/'
           publishLocation: Container
           artifactName: Loc
           condition: ${{ parameters.condition }}
\ No newline at end of file
diff --git a/eng/common/core-templates/job/publish-build-assets.yml b/eng/common/core-templates/job/publish-build-assets.yml
index 3d3356e3196..b103b7ee168 100644
--- a/eng/common/core-templates/job/publish-build-assets.yml
+++ b/eng/common/core-templates/job/publish-build-assets.yml
@@ -32,6 +32,8 @@ parameters:
 
   is1ESPipeline: ''
 
+  repositoryAlias: self
+
 jobs:
 - job: Asset_Registry_Publish
 
@@ -72,7 +74,7 @@ jobs:
     - 'Illegal entry point, is1ESPipeline is not defined. Repository yaml should not directly reference templates in core-templates folder.': error
 
   - ${{ if and(eq(parameters.runAsPublic, 'false'), ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:
-    - checkout: self
+    - checkout: ${{ parameters.repositoryAlias }}
       fetchDepth: 3
       clean: true
       
@@ -93,7 +95,7 @@ jobs:
         azureSubscription: "Darc: Maestro Production"
         scriptType: ps
         scriptLocation: scriptPath
-        scriptPath: $(Build.SourcesDirectory)/eng/common/sdk-task.ps1
+        scriptPath: $(System.DefaultWorkingDirectory)/eng/common/sdk-task.ps1
         arguments: -task PublishBuildAssets -restore -msbuildEngine dotnet
           /p:ManifestsPath='$(Build.StagingDirectory)/Download/AssetManifests'
           /p:MaestroApiEndpoint=https://maestro.dot.net
@@ -113,7 +115,7 @@ jobs:
           Add-Content -Path $filePath -Value "$(DefaultChannels)"
           Add-Content -Path $filePath -Value $(IsStableBuild)
 
-          $symbolExclusionfile = "$(Build.SourcesDirectory)/eng/SymbolPublishingExclusionsFile.txt"
+          $symbolExclusionfile = "$(System.DefaultWorkingDirectory)/eng/SymbolPublishingExclusionsFile.txt"
           if (Test-Path -Path $symbolExclusionfile)
           {
             Write-Host "SymbolExclusionFile exists"
@@ -142,7 +144,7 @@ jobs:
           azureSubscription: "Darc: Maestro Production"
           scriptType: ps
           scriptLocation: scriptPath
-          scriptPath: $(Build.SourcesDirectory)/eng/common/post-build/publish-using-darc.ps1
+          scriptPath: $(System.DefaultWorkingDirectory)/eng/common/post-build/publish-using-darc.ps1
           arguments: >
             -BuildId $(BARBuildId)
             -PublishingInfraVersion 3
diff --git a/eng/common/core-templates/job/source-build.yml b/eng/common/core-templates/job/source-build.yml
index c4713c8b6ed..d47f09d58fd 100644
--- a/eng/common/core-templates/job/source-build.yml
+++ b/eng/common/core-templates/job/source-build.yml
@@ -26,6 +26,8 @@ parameters:
   #   Specifies the build script to invoke to perform the build in the repo. The default
   #   './build.sh' should work for typical Arcade repositories, but this is customizable for
   #   difficult situations.
+  # buildArguments: ''
+  #   Specifies additional build arguments to pass to the build script.
   # jobProperties: {}
   #   A list of job properties to inject at the top level, for potential extensibility beyond
   #   container and pool.
diff --git a/eng/common/core-templates/job/source-index-stage1.yml b/eng/common/core-templates/job/source-index-stage1.yml
index 205fb5b3a39..662b9fcce15 100644
--- a/eng/common/core-templates/job/source-index-stage1.yml
+++ b/eng/common/core-templates/job/source-index-stage1.yml
@@ -1,7 +1,7 @@
 parameters:
   runAsPublic: false
-  sourceIndexUploadPackageVersion: 2.0.0-20240522.1
-  sourceIndexProcessBinlogPackageVersion: 1.0.1-20240522.1
+  sourceIndexUploadPackageVersion: 2.0.0-20250425.2
+  sourceIndexProcessBinlogPackageVersion: 1.0.1-20250425.2
   sourceIndexPackageSource: https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-tools/nuget/v3/index.json
   sourceIndexBuildCommand: powershell -NoLogo -NoProfile -ExecutionPolicy Bypass -Command "eng/common/build.ps1 -restore -build -binarylog -ci"
   preSteps: []
@@ -66,7 +66,7 @@ jobs:
   - script: ${{ parameters.sourceIndexBuildCommand }}
     displayName: Build Repository
 
-  - script: $(Agent.TempDirectory)/.source-index/tools/BinLogToSln -i $(BinlogPath) -r $(Build.SourcesDirectory) -n $(Build.Repository.Name) -o .source-index/stage1output
+  - script: $(Agent.TempDirectory)/.source-index/tools/BinLogToSln -i $(BinlogPath) -r $(System.DefaultWorkingDirectory) -n $(Build.Repository.Name) -o .source-index/stage1output
     displayName: Process Binlog into indexable sln
 
   - ${{ if and(eq(parameters.runAsPublic, 'false'), ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:
diff --git a/eng/common/core-templates/jobs/codeql-build.yml b/eng/common/core-templates/jobs/codeql-build.yml
index f2144252cc6..4571a7864df 100644
--- a/eng/common/core-templates/jobs/codeql-build.yml
+++ b/eng/common/core-templates/jobs/codeql-build.yml
@@ -25,7 +25,7 @@ jobs:
       - name: DefaultGuardianVersion
         value: 0.109.0
       - name: GuardianPackagesConfigFile
-        value: $(Build.SourcesDirectory)\eng\common\sdl\packages.config
+        value: $(System.DefaultWorkingDirectory)\eng\common\sdl\packages.config
       - name: GuardianVersion
         value: ${{ coalesce(parameters.overrideGuardianVersion, '$(DefaultGuardianVersion)') }}
   
diff --git a/eng/common/core-templates/jobs/jobs.yml b/eng/common/core-templates/jobs/jobs.yml
index ea69be4341c..3129670b338 100644
--- a/eng/common/core-templates/jobs/jobs.yml
+++ b/eng/common/core-templates/jobs/jobs.yml
@@ -43,6 +43,7 @@ parameters:
 
   artifacts: {}
   is1ESPipeline: ''
+  repositoryAlias: self
 
 # Internal resources (telemetry, microbuild) can only be accessed from non-public projects,
 # and some (Microbuild) should only be applied to non-PR cases for internal builds.
@@ -117,3 +118,4 @@ jobs:
         enablePublishBuildArtifacts: ${{ parameters.enablePublishBuildArtifacts }}
         artifactsPublishingAdditionalParameters: ${{ parameters.artifactsPublishingAdditionalParameters }}
         signingValidationAdditionalParameters: ${{ parameters.signingValidationAdditionalParameters }}
+        repositoryAlias: ${{ parameters.repositoryAlias }}
diff --git a/eng/common/core-templates/post-build/post-build.yml b/eng/common/core-templates/post-build/post-build.yml
index 454fd75c7af..2ee8bbfff54 100644
--- a/eng/common/core-templates/post-build/post-build.yml
+++ b/eng/common/core-templates/post-build/post-build.yml
@@ -44,6 +44,11 @@ parameters:
     displayName: Publish installers and checksums
     type: boolean
     default: true
+    
+  - name: requireDefaultChannels
+    displayName: Fail the build if there are no default channel(s) registrations for the current build
+    type: boolean
+    default: false
 
   - name: SDLValidationParameters
     type: object
@@ -144,7 +149,7 @@ stages:
         - task: PowerShell@2
           displayName: Validate
           inputs:
-            filePath: $(Build.SourcesDirectory)/eng/common/post-build/nuget-validation.ps1
+            filePath: $(System.DefaultWorkingDirectory)/eng/common/post-build/nuget-validation.ps1
             arguments: -PackagesPath $(Build.ArtifactStagingDirectory)/PackageArtifacts/
 
     - job:
@@ -201,7 +206,7 @@ stages:
             filePath: eng\common\sdk-task.ps1
             arguments: -task SigningValidation -restore -msbuildEngine vs
               /p:PackageBasePath='$(Build.ArtifactStagingDirectory)/PackageArtifacts'
-              /p:SignCheckExclusionsFile='$(Build.SourcesDirectory)/eng/SignCheckExclusionsFile.txt'
+              /p:SignCheckExclusionsFile='$(System.DefaultWorkingDirectory)/eng/SignCheckExclusionsFile.txt'
               ${{ parameters.signingValidationAdditionalParameters }}
 
         - template: /eng/common/core-templates/steps/publish-logs.yml
@@ -251,7 +256,7 @@ stages:
         - task: PowerShell@2
           displayName: Validate
           inputs:
-            filePath: $(Build.SourcesDirectory)/eng/common/post-build/sourcelink-validation.ps1
+            filePath: $(System.DefaultWorkingDirectory)/eng/common/post-build/sourcelink-validation.ps1
             arguments: -InputPath $(Build.ArtifactStagingDirectory)/BlobArtifacts/ 
               -ExtractPath $(Agent.BuildDirectory)/Extract/ 
               -GHRepoName $(Build.Repository.Name) 
@@ -306,11 +311,12 @@ stages:
             azureSubscription: "Darc: Maestro Production"
             scriptType: ps
             scriptLocation: scriptPath
-            scriptPath: $(Build.SourcesDirectory)/eng/common/post-build/publish-using-darc.ps1
+            scriptPath: $(System.DefaultWorkingDirectory)/eng/common/post-build/publish-using-darc.ps1
             arguments: >
               -BuildId $(BARBuildId)
               -PublishingInfraVersion ${{ parameters.publishingInfraVersion }}
               -AzdoToken '$(System.AccessToken)'
               -WaitPublishingFinish true
+              -RequireDefaultChannels ${{ parameters.requireDefaultChannels }}
               -ArtifactsPublishingAdditionalParameters '${{ parameters.artifactsPublishingAdditionalParameters }}'
               -SymbolPublishingAdditionalParameters '${{ parameters.symbolPublishingAdditionalParameters }}'
diff --git a/eng/common/core-templates/post-build/setup-maestro-vars.yml b/eng/common/core-templates/post-build/setup-maestro-vars.yml
index f7602980dbe..a7abd58c4bb 100644
--- a/eng/common/core-templates/post-build/setup-maestro-vars.yml
+++ b/eng/common/core-templates/post-build/setup-maestro-vars.yml
@@ -36,7 +36,7 @@ steps:
             $AzureDevOpsBuildId = $Env:Build_BuildId
           }
           else {
-            . $(Build.SourcesDirectory)\eng\common\tools.ps1
+            . $(System.DefaultWorkingDirectory)\eng\common\tools.ps1
             $darc = Get-Darc
             $buildInfo = & $darc get-build `
               --id ${{ parameters.BARBuildId }} `
diff --git a/eng/common/core-templates/steps/enable-internal-sources.yml b/eng/common/core-templates/steps/enable-internal-sources.yml
index 64f881bffc3..4085512b690 100644
--- a/eng/common/core-templates/steps/enable-internal-sources.yml
+++ b/eng/common/core-templates/steps/enable-internal-sources.yml
@@ -17,8 +17,8 @@ steps:
     - task: PowerShell@2
       displayName: Setup Internal Feeds
       inputs:
-        filePath: $(Build.SourcesDirectory)/eng/common/SetupNugetSources.ps1
-        arguments: -ConfigFile $(Build.SourcesDirectory)/NuGet.config -Password $Env:Token
+        filePath: $(System.DefaultWorkingDirectory)/eng/common/SetupNugetSources.ps1
+        arguments: -ConfigFile $(System.DefaultWorkingDirectory)/NuGet.config -Password $Env:Token
       env:
         Token: ${{ parameters.legacyCredential }}
   # If running on dnceng (internal project), just use the default behavior for NuGetAuthenticate.
@@ -29,8 +29,8 @@ steps:
       - task: PowerShell@2
         displayName: Setup Internal Feeds
         inputs:
-          filePath: $(Build.SourcesDirectory)/eng/common/SetupNugetSources.ps1
-          arguments: -ConfigFile $(Build.SourcesDirectory)/NuGet.config
+          filePath: $(System.DefaultWorkingDirectory)/eng/common/SetupNugetSources.ps1
+          arguments: -ConfigFile $(System.DefaultWorkingDirectory)/NuGet.config
     - ${{ else }}:
       - template: /eng/common/templates/steps/get-federated-access-token.yml
         parameters:
@@ -39,8 +39,8 @@ steps:
       - task: PowerShell@2
         displayName: Setup Internal Feeds
         inputs:
-          filePath: $(Build.SourcesDirectory)/eng/common/SetupNugetSources.ps1
-          arguments: -ConfigFile $(Build.SourcesDirectory)/NuGet.config -Password $(dnceng-artifacts-feeds-read-access-token)
+          filePath: $(System.DefaultWorkingDirectory)/eng/common/SetupNugetSources.ps1
+          arguments: -ConfigFile $(System.DefaultWorkingDirectory)/NuGet.config -Password $(dnceng-artifacts-feeds-read-access-token)
   # This is required in certain scenarios to install the ADO credential provider.
   # It installed by default in some msbuild invocations (e.g. VS msbuild), but needs to be installed for others
   # (e.g. dotnet msbuild).
diff --git a/eng/common/core-templates/steps/generate-sbom.yml b/eng/common/core-templates/steps/generate-sbom.yml
index 56a09009482..7f5b84c4cb8 100644
--- a/eng/common/core-templates/steps/generate-sbom.yml
+++ b/eng/common/core-templates/steps/generate-sbom.yml
@@ -6,7 +6,7 @@
 
 parameters:
   PackageVersion: 9.0.0
-  BuildDropPath: '$(Build.SourcesDirectory)/artifacts'
+  BuildDropPath: '$(System.DefaultWorkingDirectory)/artifacts'
   PackageName: '.NET'
   ManifestDirPath: $(Build.ArtifactStagingDirectory)/sbom
   IgnoreDirectories: ''
diff --git a/eng/common/core-templates/steps/publish-logs.yml b/eng/common/core-templates/steps/publish-logs.yml
index 80788c52319..0623ac6e112 100644
--- a/eng/common/core-templates/steps/publish-logs.yml
+++ b/eng/common/core-templates/steps/publish-logs.yml
@@ -12,22 +12,22 @@ steps:
   inputs:
     targetType: inline
     script: |
-      New-Item -ItemType Directory $(Build.SourcesDirectory)/PostBuildLogs/${{parameters.StageLabel}}/${{parameters.JobLabel}}/
-      Move-Item -Path $(Build.SourcesDirectory)/artifacts/log/Debug/* $(Build.SourcesDirectory)/PostBuildLogs/${{parameters.StageLabel}}/${{parameters.JobLabel}}/
+      New-Item -ItemType Directory $(System.DefaultWorkingDirectory)/PostBuildLogs/${{parameters.StageLabel}}/${{parameters.JobLabel}}/
+      Move-Item -Path $(System.DefaultWorkingDirectory)/artifacts/log/Debug/* $(System.DefaultWorkingDirectory)/PostBuildLogs/${{parameters.StageLabel}}/${{parameters.JobLabel}}/
   continueOnError: true
   condition: always()
     
 - task: PowerShell@2
   displayName: Redact Logs
   inputs:
-    filePath: $(Build.SourcesDirectory)/eng/common/post-build/redact-logs.ps1
+    filePath: $(System.DefaultWorkingDirectory)/eng/common/post-build/redact-logs.ps1
     # For now this needs to have explicit list of all sensitive data. Taken from eng/publishing/v3/publish.yml
-    # Sensitive data can as well be added to $(Build.SourcesDirectory)/eng/BinlogSecretsRedactionFile.txt'
+    # Sensitive data can as well be added to $(System.DefaultWorkingDirectory)/eng/BinlogSecretsRedactionFile.txt'
     #  If the file exists - sensitive data for redaction will be sourced from it
     #  (single entry per line, lines starting with '# ' are considered comments and skipped)
-    arguments: -InputPath '$(Build.SourcesDirectory)/PostBuildLogs' 
+    arguments: -InputPath '$(System.DefaultWorkingDirectory)/PostBuildLogs' 
       -BinlogToolVersion ${{parameters.BinlogToolVersion}}
-      -TokensFilePath '$(Build.SourcesDirectory)/eng/BinlogSecretsRedactionFile.txt'
+      -TokensFilePath '$(System.DefaultWorkingDirectory)/eng/BinlogSecretsRedactionFile.txt'
       '$(publishing-dnceng-devdiv-code-r-build-re)'
       '$(MaestroAccessToken)'
       '$(dn-bot-all-orgs-artifact-feeds-rw)'
@@ -42,7 +42,7 @@ steps:
 - task: CopyFiles@2
   displayName: Gather post build logs
   inputs:
-    SourceFolder: '$(Build.SourcesDirectory)/PostBuildLogs'
+    SourceFolder: '$(System.DefaultWorkingDirectory)/PostBuildLogs'
     Contents: '**'
     TargetFolder: '$(Build.ArtifactStagingDirectory)/PostBuildLogs'
 
diff --git a/eng/common/core-templates/steps/source-build.yml b/eng/common/core-templates/steps/source-build.yml
index 2915d29bb7f..730f7ab2b67 100644
--- a/eng/common/core-templates/steps/source-build.yml
+++ b/eng/common/core-templates/steps/source-build.yml
@@ -79,6 +79,7 @@ steps:
     ${{ coalesce(parameters.platform.buildScript, './build.sh') }} --ci \
       --configuration $buildConfig \
       --restore --build --pack $publishArgs -bl \
+      ${{ parameters.platform.buildArguments }} \
       $officialBuildArgs \
       $internalRuntimeDownloadArgs \
       $internalRestoreArgs \
@@ -96,7 +97,7 @@ steps:
 - task: CopyFiles@2
   displayName: Prepare BuildLogs staging directory
   inputs:
-    SourceFolder: '$(Build.SourcesDirectory)'
+    SourceFolder: '$(System.DefaultWorkingDirectory)'
     Contents: |
       **/*.log
       **/*.binlog
@@ -125,5 +126,5 @@ steps:
   parameters:
     displayName: Component Detection (Exclude upstream cache)
     is1ESPipeline: ${{ parameters.is1ESPipeline }}
-    componentGovernanceIgnoreDirectories: '$(Build.SourcesDirectory)/artifacts/sb/src/artifacts/obj/source-built-upstream-cache'
+    componentGovernanceIgnoreDirectories: '$(System.DefaultWorkingDirectory)/artifacts/sb/src/artifacts/obj/source-built-upstream-cache'
     disableComponentGovernance: ${{ eq(variables['System.TeamProject'], 'public') }}
diff --git a/eng/common/internal/NuGet.config b/eng/common/internal/NuGet.config
index 19d3d311b16..f70261ed689 100644
--- a/eng/common/internal/NuGet.config
+++ b/eng/common/internal/NuGet.config
@@ -4,4 +4,7 @@
     <clear />
     <add key="dotnet-core-internal-tooling" value="https://pkgs.dev.azure.com/devdiv/_packaging/dotnet-core-internal-tooling/nuget/v3/index.json" />
   </packageSources>
+  <packageSourceMapping>
+    <clear />
+  </packageSourceMapping>
 </configuration>
diff --git a/eng/common/post-build/publish-using-darc.ps1 b/eng/common/post-build/publish-using-darc.ps1
index 90b58e32a87..a261517ef90 100644
--- a/eng/common/post-build/publish-using-darc.ps1
+++ b/eng/common/post-build/publish-using-darc.ps1
@@ -5,7 +5,8 @@ param(
   [Parameter(Mandatory=$false)][string] $MaestroApiEndPoint = 'https://maestro.dot.net',
   [Parameter(Mandatory=$true)][string] $WaitPublishingFinish,
   [Parameter(Mandatory=$false)][string] $ArtifactsPublishingAdditionalParameters,
-  [Parameter(Mandatory=$false)][string] $SymbolPublishingAdditionalParameters
+  [Parameter(Mandatory=$false)][string] $SymbolPublishingAdditionalParameters,
+  [Parameter(Mandatory=$false)][string] $RequireDefaultChannels
 )
 
 try {
@@ -33,6 +34,10 @@ try {
   if ("false" -eq $WaitPublishingFinish) {
     $optionalParams.Add("--no-wait") | Out-Null
   }
+  
+  if ("true" -eq $RequireDefaultChannels) {
+    $optionalParams.Add("--default-channels-required") | Out-Null
+  }
 
   & $darc add-build-to-channel `
     --id $buildId `
diff --git a/eng/common/template-guidance.md b/eng/common/template-guidance.md
index 98bbc1ded0b..4bf4cf41bd7 100644
--- a/eng/common/template-guidance.md
+++ b/eng/common/template-guidance.md
@@ -50,7 +50,7 @@ extends:
           - task: CopyFiles@2
               displayName: Gather build output
               inputs:
-                SourceFolder: '$(Build.SourcesDirectory)/artifacts/marvel'
+                SourceFolder: '$(System.DefaultWorkingDirectory)/artifacts/marvel'
                 Contents: '**'
                 TargetFolder: '$(Build.ArtifactStagingDirectory)/artifacts/marvel'
 ```
diff --git a/eng/common/templates-official/job/job.yml b/eng/common/templates-official/job/job.yml
index 817555505aa..81ea7a261f2 100644
--- a/eng/common/templates-official/job/job.yml
+++ b/eng/common/templates-official/job/job.yml
@@ -3,7 +3,7 @@ parameters:
   enableSbom: true
   runAsPublic: false
   PackageVersion: 9.0.0
-  BuildDropPath: '$(Build.SourcesDirectory)/artifacts'
+  BuildDropPath: '$(System.DefaultWorkingDirectory)/artifacts'
 
 jobs:
 - template: /eng/common/core-templates/job/job.yml
diff --git a/eng/common/templates-official/variables/sdl-variables.yml b/eng/common/templates-official/variables/sdl-variables.yml
index dbdd66d4a4b..f1311bbb1b3 100644
--- a/eng/common/templates-official/variables/sdl-variables.yml
+++ b/eng/common/templates-official/variables/sdl-variables.yml
@@ -4,4 +4,4 @@ variables:
 - name: DefaultGuardianVersion
   value: 0.109.0
 - name: GuardianPackagesConfigFile
-  value: $(Build.SourcesDirectory)\eng\common\sdl\packages.config
\ No newline at end of file
+  value: $(System.DefaultWorkingDirectory)\eng\common\sdl\packages.config
\ No newline at end of file
diff --git a/eng/common/templates/job/job.yml b/eng/common/templates/job/job.yml
index d1aeb92fcea..5bdd3dd85fd 100644
--- a/eng/common/templates/job/job.yml
+++ b/eng/common/templates/job/job.yml
@@ -6,7 +6,7 @@ parameters:
   enableSbom: true
   runAsPublic: false
   PackageVersion: 9.0.0
-  BuildDropPath: '$(Build.SourcesDirectory)/artifacts'
+  BuildDropPath: '$(System.DefaultWorkingDirectory)/artifacts'
 
 jobs:
 - template: /eng/common/core-templates/job/job.yml
@@ -75,7 +75,7 @@ jobs:
         parameters:
           is1ESPipeline: false
           args:
-            targetPath: '$(Build.SourcesDirectory)\eng\common\BuildConfiguration'
+            targetPath: '$(System.DefaultWorkingDirectory)\eng\common\BuildConfiguration'
             artifactName: 'BuildConfiguration'
             displayName: 'Publish build retry configuration'
             continueOnError: true
diff --git a/eng/common/tools.ps1 b/eng/common/tools.ps1
index a46b6deb759..9b3ad8840fd 100644
--- a/eng/common/tools.ps1
+++ b/eng/common/tools.ps1
@@ -42,7 +42,7 @@
 [bool]$useInstalledDotNetCli = if (Test-Path variable:useInstalledDotNetCli) { $useInstalledDotNetCli } else { $true }
 
 # Enable repos to use a particular version of the on-line dotnet-install scripts.
-#    default URL: https://dotnet.microsoft.com/download/dotnet/scripts/v1/dotnet-install.ps1
+#    default URL: https://builds.dotnet.microsoft.com/dotnet/scripts/v1/dotnet-install.ps1
 [string]$dotnetInstallScriptVersion = if (Test-Path variable:dotnetInstallScriptVersion) { $dotnetInstallScriptVersion } else { 'v1' }
 
 # True to use global NuGet cache instead of restoring packages to repository-local directory.
@@ -262,7 +262,7 @@ function GetDotNetInstallScript([string] $dotnetRoot) {
   if (!(Test-Path $installScript)) {
     Create-Directory $dotnetRoot
     $ProgressPreference = 'SilentlyContinue' # Don't display the console progress UI - it's a huge perf hit
-    $uri = "https://dotnet.microsoft.com/download/dotnet/scripts/$dotnetInstallScriptVersion/dotnet-install.ps1"
+    $uri = "https://builds.dotnet.microsoft.com/dotnet/scripts/$dotnetInstallScriptVersion/dotnet-install.ps1"
 
     Retry({
       Write-Host "GET $uri"
@@ -416,7 +416,7 @@ function InitializeVisualStudioMSBuild([bool]$install, [object]$vsRequirements =
 
   # Locate Visual Studio installation or download x-copy msbuild.
   $vsInfo = LocateVisualStudio $vsRequirements
-  if ($vsInfo -ne $null) {
+  if ($vsInfo -ne $null -and $env:ForceUseXCopyMSBuild -eq $null) {
     # Ensure vsInstallDir has a trailing slash
     $vsInstallDir = Join-Path $vsInfo.installationPath "\"
     $vsMajorVersion = $vsInfo.installationVersion.Split('.')[0]
diff --git a/eng/common/tools.sh b/eng/common/tools.sh
index 1159726a10f..01b09b65796 100755
--- a/eng/common/tools.sh
+++ b/eng/common/tools.sh
@@ -54,7 +54,7 @@ warn_as_error=${warn_as_error:-true}
 use_installed_dotnet_cli=${use_installed_dotnet_cli:-true}
 
 # Enable repos to use a particular version of the on-line dotnet-install scripts.
-#    default URL: https://dotnet.microsoft.com/download/dotnet/scripts/v1/dotnet-install.sh
+#    default URL: https://builds.dotnet.microsoft.com/dotnet/scripts/v1/dotnet-install.sh
 dotnetInstallScriptVersion=${dotnetInstallScriptVersion:-'v1'}
 
 # True to use global NuGet cache instead of restoring packages to repository-local directory.
@@ -295,7 +295,7 @@ function with_retries {
 function GetDotNetInstallScript {
   local root=$1
   local install_script="$root/dotnet-install.sh"
-  local install_script_url="https://dotnet.microsoft.com/download/dotnet/scripts/$dotnetInstallScriptVersion/dotnet-install.sh"
+  local install_script_url="https://builds.dotnet.microsoft.com/dotnet/scripts/$dotnetInstallScriptVersion/dotnet-install.sh"
 
   if [[ ! -a "$install_script" ]]; then
     mkdir -p "$root"
diff --git a/global.json b/global.json
index 1d8f45a8951..f1f5836af84 100644
--- a/global.json
+++ b/global.json
@@ -1,6 +1,6 @@
 {
   "tools": {
-    "dotnet": "9.0.104",
+    "dotnet": "9.0.109",
     "runtimes": {
       "dotnet": [
         "2.1.30",
@@ -17,12 +17,12 @@
     }
   },
   "sdk": {
-    "version": "9.0.104",
+    "version": "9.0.109",
     "allowPrerelease": false,
     "rollForward": "latestPatch"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Arcade.Sdk": "9.0.0-beta.25161.4",
+    "Microsoft.DotNet.Arcade.Sdk": "9.0.0-beta.25415.3",
     "Microsoft.Build.NoTargets": "3.7.0"
   }
 }