diff --git a/src/SourceBuild/content/repo-projects/Directory.Build.targets b/src/SourceBuild/content/repo-projects/Directory.Build.targets
index d96d9edab..f541430d6 100644
--- a/src/SourceBuild/content/repo-projects/Directory.Build.targets
+++ b/src/SourceBuild/content/repo-projects/Directory.Build.targets
@@ -57,7 +57,6 @@
 
   <!-- Update NuGet feeds in the repo -->
   <Target Name="UpdateNuGetConfig"
-          BeforeTargets="Build"
           Condition="'$(NuGetConfigFile)' != '' or '@(NuGetConfigFiles)' != ''"
           Inputs="$(MSBuildProjectFullPath)"
           Outputs="$(BaseIntermediateOutputPath)UpdateNuGetConfig.complete">
@@ -146,7 +145,6 @@
   <!-- Update the SDK version in the repo's global.json file.
        This guarantees that all repositories build with the VMR's SDK version. -->
   <Target Name="UpdateGlobalJsonVersions"
-          BeforeTargets="Build"
           Condition="'$(GlobalJsonFile)' != ''"
           Inputs="$(MSBuildProjectFullPath);$(MSBuildThisFileFullPath)"
           Outputs="$(BaseIntermediateOutputPath)UpdateGlobalJsonVersions.complete">
@@ -173,8 +171,7 @@
 
   <!-- TODO: Remove when all repos use a consistent set of eng/common files: https://github.com/dotnet/source-build/issues/3710. -->
   <Target Name="UpdateEngCommonFiles"
-          Condition="'$(UpdateEngCommonFiles)' == 'true' or '$(DotNetBuildSourceOnly)' != 'true'"
-          BeforeTargets="Build">
+          Condition="'$(UpdateEngCommonFiles)' == 'true' or '$(DotNetBuildSourceOnly)' != 'true'">
     <ItemGroup>
       <OrchestratorEngCommonFile Include="$(RepositoryEngineeringDir)common\**\*" />
     </ItemGroup>
@@ -187,7 +184,6 @@
   <!-- Before a repository builds, set up the version property files that override the repo's defaults.
        There are 3 files generated -->
   <Target Name="CreateBuildInputProps"
-          BeforeTargets="Build"
           Inputs="$(MSBuildProjectFullPath)"
           Outputs="$(BaseIntermediateOutputPath)CreateBuildInputProps.complete">
     <ItemGroup>
@@ -268,31 +264,25 @@
              StopOnFirstFailure="true" />
   </Target>
 
-  <Target Name="Build"
-          DependsOnTargets="BuildRepoReferences"
+  <Target Name="RepoBuild"
           Inputs="$(MSBuildProjectFullPath)"
-          Outputs="$(BaseIntermediateOutputPath)Build.complete">
+          Outputs="$(BaseIntermediateOutputPath)Build.complete"
+          Condition="'$(BuildCommand)' != ''"
+          DependsOnTargets="BuildRepoReferences;
+                            UpdateNuGetConfig;
+                            UpdateGlobalJsonVersions;
+                            CreateBuildInputProps;
+                            UpdateEngCommonFiles;
+                            SetSourceBuiltSdkOverrides">
     <Exec Command="$(DotnetTool) build-server shutdown" />
 
     <Message Importance="High" Text="[$([System.DateTime]::Now.ToString('HH:mm:ss.ff'))] Building $(RepositoryName)" />
-    <Message Importance="High" Text="Running command:" Condition="'$(BuildCommand)' != ''" />
-    <Message Importance="High" Text="  $(BuildCommand)" Condition="'$(BuildCommand)' != ''" />
-    <Message Importance="High" Text="  Log: $(RepoConsoleLogFile)" Condition="'$(BuildCommand)' != '' and '$(MinimalConsoleLogOutput)' == 'true'" />
-    <Message Importance="High" Text="  With Environment Variables:" Condition="'$(BuildCommand)' != ''" />
-    <Message Importance="High" Text="    %(EnvironmentVariables.Identity)" Condition="'$(BuildCommand)' != ''" />
-    <CallTarget Targets="RepoBuild" />
-    <Message Importance="High" Text="[$([System.DateTime]::Now.ToString('HH:mm:ss.ff'))] Building $(RepositoryName)...done" />
+    <Message Importance="High" Text="Running command:" />
+    <Message Importance="High" Text="  $(BuildCommand)" />
+    <Message Importance="High" Text="  Log: $(RepoConsoleLogFile)" Condition="'$(MinimalConsoleLogOutput)' == 'true'" />
+    <Message Importance="High" Text="  With Environment Variables:"/>
+    <Message Importance="High" Text="    %(EnvironmentVariables.Identity)" />
 
-    <MakeDir Directories="$(BaseIntermediateOutputPath)" />
-    <Touch Files="$(BaseIntermediateOutputPath)Build.complete" AlwaysCreate="true">
-      <Output TaskParameter="TouchedFiles" ItemName="FileWrites" />
-    </Touch>
-
-    <OnError ExecuteTargets="ReportRepoError" />
-  </Target>
-
-  <Target Name="RepoBuild"
-          Condition="'$(BuildCommand)' != ''">
     <Message Text="DirSize Before Building $(RepositoryName)" Importance="High"
              Condition=" '$(CleanWhileBuilding)' == 'true' and '$(BuildOS)' != 'windows'" />
     <Exec Command="df -h $(RepoRoot)"
@@ -315,16 +305,27 @@
 
     <Exec Command="$(FullCommand)"
           WorkingDirectory="$(ProjectDirectory)"
-          EnvironmentVariables="@(EnvironmentVariables)"
-          IgnoreStandardErrorWarningFormat="true" />
+          EnvironmentVariables="@(EnvironmentVariables)" />
+
+    <Message Importance="High" Text="[$([System.DateTime]::Now.ToString('HH:mm:ss.ff'))] Building $(RepositoryName)...done" />
+
+    <MakeDir Directories="$(BaseIntermediateOutputPath)" />
+    <Touch Files="$(BaseIntermediateOutputPath)Build.complete" AlwaysCreate="true">
+      <Output TaskParameter="TouchedFiles" ItemName="FileWrites" />
+    </Touch>
+
+    <!-- Propagate errors to the output when using the minimal console log feature. -->
+    <OnError ExecuteTargets="LogRepoBuildError" Condition="'$(MinimalConsoleLogOutput)' == 'true'" />
   </Target>
 
-  <Target Name="ReportRepoError">
+  <Target Name="LogRepoBuildError">
     <Message Importance="High" Text="$([System.IO.File]::ReadAllText('$(RepoConsoleLogFile)'))" Condition="Exists('$(RepoConsoleLogFile)') and '$(MinimalConsoleLogOutput)' == 'true'" />
     <Message Importance="High" Text="'$(RepositoryName)' failed during build." />
     <Message Importance="High" Text="See '$(RepoConsoleLogFile)' for more information." Condition="Exists('$(RepoConsoleLogFile)') and '$(MinimalConsoleLogOutput)' == 'true'" />
   </Target>
 
+  <Target Name="Build" DependsOnTargets="BuildRepoReferences;RepoBuild" />
+
   <Target Name="Package" AfterTargets="Build" />
 
   <Target Name="GatherBuiltPackages">
@@ -643,7 +644,6 @@
   </Target>
 
   <Target Name="SetSourceBuiltSdkOverrides"
-          BeforeTargets="Build"
           Condition="'@(SourceBuiltSdkOverride)' != ''">
     <ItemGroup>
       <EnvironmentVariables Include="SOURCE_BUILT_SDK_ID_%(SourceBuiltSdkOverride.Group)=%(SourceBuiltSdkOverride.Identity)" />
diff --git a/src/SourceBuild/content/repo-projects/package-source-build.proj b/src/SourceBuild/content/repo-projects/package-source-build.proj
index 9703ad0c0..d95a7336f 100644
--- a/src/SourceBuild/content/repo-projects/package-source-build.proj
+++ b/src/SourceBuild/content/repo-projects/package-source-build.proj
@@ -13,7 +13,7 @@
 
   <Target Name="CustomRepoBuild"
           AfterTargets="RepoBuild"
-          DependsOnTargets="DetermineSourceBuiltSdkVersion">
+          DependsOnTargets="CreateBuildInputProps;DetermineSourceBuiltSdkVersion">
     <!-- Copy PVP to packages dir in order to package them together -->
     <Copy SourceFiles="$(CurrentSourceBuiltPackageVersionPropsPath)" DestinationFiles="$(SourceBuiltPackagesPath)PackageVersions.props" />
 
diff --git a/src/SourceBuild/content/repo-projects/runtime.proj b/src/SourceBuild/content/repo-projects/runtime.proj
index dc1110328..35bbd9b03 100644
--- a/src/SourceBuild/content/repo-projects/runtime.proj
+++ b/src/SourceBuild/content/repo-projects/runtime.proj
@@ -3,14 +3,20 @@
   <PropertyGroup>
     <LogVerbosityOptOut>true</LogVerbosityOptOut>
 
+    <_platformIndex>$(NETCoreSdkRuntimeIdentifier.LastIndexOf('-'))</_platformIndex>
+    <RuntimeOS>$(NETCoreSdkRuntimeIdentifier.Substring(0, $(_platformIndex)))</RuntimeOS>
+
+    <_platformIndex>$(NETCoreSdkPortableRuntimeIdentifier.LastIndexOf('-'))</_platformIndex>
+    <BaseOS>$(NETCoreSdkPortableRuntimeIdentifier.Substring(0, $(_platformIndex)))-$(TargetArchitecture)</BaseOS>
+
     <!-- Use the repo root build script -->
     <BuildScript>$(ProjectDirectory)build$(ShellExtension)</BuildScript>
 
     <BuildArgs>$(BuildArgs) $(FlagParameterPrefix)arch $(TargetArchitecture)</BuildArgs>
     <BuildArgs>$(BuildArgs) $(FlagParameterPrefix)os $(TargetOS)</BuildArgs>
     <BuildArgs>$(BuildArgs) /p:TargetRid=$(TargetRid)</BuildArgs>
-    <BuildArgs>$(BuildArgs) /p:RuntimeOS=$(TargetOS)</BuildArgs>
-    <BuildArgs>$(BuildArgs) /p:BaseOS=$(PortableRid)</BuildArgs>
+    <BuildArgs>$(BuildArgs) /p:RuntimeOS=$(RuntimeOS)</BuildArgs>
+    <BuildArgs>$(BuildArgs) /p:BaseOS=$(BaseOS)</BuildArgs>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(DotNetBuildSourceOnly)' == 'true'">
diff --git a/src/SourceBuild/content/repo-projects/sdk.proj b/src/SourceBuild/content/repo-projects/sdk.proj
index b4b91ed27..69c6a2826 100644
--- a/src/SourceBuild/content/repo-projects/sdk.proj
+++ b/src/SourceBuild/content/repo-projects/sdk.proj
@@ -3,11 +3,6 @@
   <PropertyGroup>
     <LogVerbosityOptOut>true</LogVerbosityOptOut>
 
-    <!-- Propagate RID set in source-build to sdk repo -->
-    <_platformIndex>$(NETCoreSdkPortableRuntimeIdentifier.LastIndexOf('-'))</_platformIndex>
-    <_baseOS>$(NETCoreSdkPortableRuntimeIdentifier.Substring(0, $(_platformIndex)))</_baseOS>
-    <_baseOS Condition="'$(PortableBuild)' == 'true'">$(TargetOS)</_baseOS>
-
     <BuildArgs>$(BuildArgs) /p:PackageProjectUrl=https://github.com/dotnet/sdk</BuildArgs>
     <BuildArgs>$(BuildArgs) /p:PortableRid=$(PortableRid)</BuildArgs>
     <BuildArgs>$(BuildArgs) /p:TargetRid=$(TargetRid)</BuildArgs>
diff --git a/src/SourceBuild/content/repo-projects/source-build-reference-packages.proj b/src/SourceBuild/content/repo-projects/source-build-reference-packages.proj
index beeb213fd..a3bf43dae 100644
--- a/src/SourceBuild/content/repo-projects/source-build-reference-packages.proj
+++ b/src/SourceBuild/content/repo-projects/source-build-reference-packages.proj
@@ -20,7 +20,7 @@
   </PropertyGroup>
 
   <Target Name="AddLocalNuGetPackageCacheDirectory"
-          BeforeTargets="Build">
+          BeforeTargets="UpdateNuGetConfig">
     <MakeDir Condition="'$(LocalNuGetPackageCacheDirectory)' != ''"
              Directories="$(LocalNuGetPackageCacheDirectory)" />