Flow NuGetPackageRoot even on non-Restore paths

Author: sharwell

src/Microsoft.DotNet.Arcade.Sdk/tools/Build.proj

@@ -133,7 +133,7 @@
       <_CommonProps Include="VCTargetsPath=$([MSBuild]::ValueOrDefault('$(VCTargetsPath)', '$([MSBuild]::GetVsInstallRoot())\Common7\IDE\VC\VCTargets\'))" Condition="'$(MSBuildRuntimeType)' != 'Core'"/>
     </ItemGroup>
 
-    <ItemGroup Condition="'$(Restore)' == 'true'">
+    <ItemGroup>
       <_RestoreToolsProps Include="@(_CommonProps)"/>
       <_RestoreToolsProps Include="BaseIntermediateOutputPath=$(ArtifactsToolsetDir)Common"/>
       <_RestoreToolsProps Include="ExcludeRestorePackageImports=true"/>
@@ -150,28 +150,32 @@
     </ItemGroup>
 
     <!--
-      Restore built-in tools.
+      Builds from the 'internal' project, and only those, can download the .net Runtime 
+      from a private location.
+    -->
+    <ItemGroup Condition="'$(SYSTEM_TEAMPROJECT)' == 'internal'">
+      <_RestoreToolsProps Include="DotNetRuntimeSourceFeed=$(DotNetRuntimeSourceFeed)"/>
+      <_RestoreToolsProps Include="DotNetRuntimeSourceFeedKey=$(DotNetRuntimeSourceFeedKey)"/>
+    </ItemGroup>
+
+    <!--
+      Restore built-in tools if requested, and extract information from the NuGet restore output.
     -->
     <MSBuild Projects="Tools.proj"
-             Targets="RestoreAndReturnNuGetPackageRoot"
+             Targets="Restore"
              Properties="@(_RestoreToolsProps);_NETCORE_ENGINEERING_TELEMETRY=Restore"
-             Condition="'$(Restore)' == 'true'">
+             Condition="'$(Restore)' == 'true'"/>
+
+    <MSBuild Projects="Tools.proj"
+             Targets="ReturnNuGetPackageRoot"
+             Properties="@(_RestoreToolsProps);_NETCORE_ENGINEERING_TELEMETRY=ReturnNuGetPackageRoot">
       <Output TaskParameter="TargetOutputs" ItemName="_RestoreToolsOutput" />
     </MSBuild>
 
-    <ItemGroup Condition="'$(Restore)' == 'true'">
+    <ItemGroup>
       <_CommonProps Include="@(_RestoreToolsOutput->'NuGetPackageRoot=%(Identity)')"/>
     </ItemGroup>
 
-    <!--
-      Builds from the 'internal' project, and only those, can download the .net Runtime 
-      from a private location.
-    -->
-    <ItemGroup Condition="'$(SYSTEM_TEAMPROJECT)' == 'internal'">
-      <_RestoreToolsProps Include="DotNetRuntimeSourceFeed=$(DotNetRuntimeSourceFeed)"/>
-      <_RestoreToolsProps Include="DotNetRuntimeSourceFeedKey=$(DotNetRuntimeSourceFeedKey)"/>
-    </ItemGroup>
-
     <ItemGroup>
       <_PublishProps Include="@(_CommonProps)"/>
 

src/Microsoft.DotNet.Arcade.Sdk/tools/Tools.proj

@@ -86,7 +86,9 @@
         Condition="'$(Restore)' == 'true'"/>
   </Target>
 
-  <Target Name="RestoreAndReturnNuGetPackageRoot" DependsOnTargets="Restore" Returns="$(NuGetPackageRoot)" />
+  <Target Name="ReturnNuGetPackageRoot" Returns="$(NuGetPackageRoot)">
+    <Error Text="Unable to determine 'NuGetPackageRoot' prior to restore." Condition="'$(NuGetPackageRoot)' == ''" />
+  </Target>
 
   <Import Project="SourceBuild/SourceBuildArcadeTools.targets" Condition="'$(ArcadeBuildFromSource)' == 'true' or
                                                                           '$(DotNetBuildRepo)' == 'true' or