NuGet Targets file doesn't include WinMDs from SDKReference targets

[jonwis]

I have this in my vcxproj:

  <ItemGroup>
    <SDKReference Include="CppUnitTestFramework.Universal, Version=$(UnitTestPlatformVersion)" />
    <SDKReference Include="TestPlatform.Universal, Version=$(UnitTestPlatformVersion)" />
  </ItemGroup>

cppwinrt/nuget/Microsoft.Windows.CppWinRT.targets

Lines 250 to 262 in aeb78bb

	<Target Name="GetCppWinRTDirectWinMDReferences"
	DependsOnTargets="ResolveAssemblyReferences;$(GetCppWinRTDirectWinMDReferencesDependsOn)"
	Returns="@(CppWinRTDirectWinMDReferences)">
	<ItemGroup>
	<_CppWinRTDirectWinMDReferences Remove="@(_CppWinRTDirectWinMDReferences)" />
	<_CppWinRTDirectWinMDReferences Include="@(ReferencePath)" Condition="'%(ReferencePath.IsSystemReference)' != 'true' and '%(ReferencePath.WinMDFile)' == 'true' and '%(ReferencePath.ReferenceSourceTarget)' == 'ResolveAssemblyReference'" />
	<CppWinRTDirectWinMDReferences Remove="@(CppWinRTDirectWinMDReferences)"/>
	<CppWinRTDirectWinMDReferences Include="@(_CppWinRTDirectWinMDReferences)">
	<WinMDPath>%(FullPath)</WinMDPath>
	</CppWinRTDirectWinMDReferences>
	</ItemGroup>
	<Message Text="CppWinRTDirectWinMDReferences: @(CppWinRTDirectWinMDReferences->'%(WinMDPath)')" Importance="$(CppWinRTVerbosity)"/>
	</Target>

I added a reference to the MSTest / Visual Studio Test SDK to add tests, but couldn't #include <winrt/Microsoft.VisualStudio.TestPlatform.TestExecutor.WinRTCore.h>, etc. Looks like the missing piece was adding this at line 256:

<_CppWinRTDirectWinMDReferences Include="@(ReferencePath)" Condition="'%(ReferencePath.WinMDFile)' == 'true' and '%(ReferencePath.ReferenceSourceTarget)' == 'ExpandSDKReference'" />

(And of course adding a DependsOnTarget for ExpandSDKReferences.)

Then it worked great! There's a CppWinRTSDKReferences variable referenced in GetCppWinRTPlatformWinMDReferences ... maybe some previous operation was supposed to populate it, and that set should be present in both places?