Generating a layout folder with the satellite assemblies only which we use to generate a language pack tarball/zip. Initially, I wanted a IncludeOnlyFilter, but couldn't quite get that to work on tar, just passing the filter in the command line didn't work because the shell does not do recursive globbing. So, I opted for the layout folder.

build/Branding.props

@@ -22,12 +22,14 @@
     <ArtifactNameSdk>dotnet-sdk-internal</ArtifactNameSdk>
     <ArtifactNameSdkDebug>dotnet-sdk-debug</ArtifactNameSdkDebug>
     <ArtifactNameCombinedHostHostFxrFrameworkSdk>dotnet-sdk</ArtifactNameCombinedHostHostFxrFrameworkSdk>
+    <ArtifactNameSdkLanguagePack>$(ArtifactNameCombinedHostHostFxrFrameworkSdk)-langpack</ArtifactNameSdkLanguagePack>
 
     <ArtifactNameWithVersionSdk>$(ArtifactNameSdk)-$(SdkVersion)-$(ProductMonikerRid)</ArtifactNameWithVersionSdk>
 
 
     <ArtifactNameWithVersionSdkDebug>$(ArtifactNameSdkDebug)-$(SdkVersion)-$(ProductMonikerRid)</ArtifactNameWithVersionSdkDebug>
     <ArtifactNameWithVersionCombinedHostHostFxrFrameworkSdk>$(ArtifactNameCombinedHostHostFxrFrameworkSdk)-$(SdkVersion)-$(ProductMonikerRid)</ArtifactNameWithVersionCombinedHostHostFxrFrameworkSdk>
+    <ArtifactNameWithVersionSdkLanguagePack>$(ArtifactNameSdkLanguagePack)-$(SdkVersion)-$(ProductMonikerRid)</ArtifactNameWithVersionSdkLanguagePack>
     <DistroSpecificArtifactNameWithVersionCombinedHostHostFxrFrameworkSdk>$(ArtifactNameCombinedHostHostFxrFrameworkSdk)-$(SdkVersion)-$(HostMonikerRid)</DistroSpecificArtifactNameWithVersionCombinedHostHostFxrFrameworkSdk>
   </PropertyGroup>
 </Project>

build/package/Archive.targets

@@ -14,7 +14,6 @@
 
     <PropertyGroup>
       <GenerateArchivesDestinationArchive>$(ArchiveOutputDirectory)/%(GenerateArchivesInputsOutputs.OutFileName)$(ArchiveExtension)</GenerateArchivesDestinationArchive>
-      <SatelliteAssemblies>*.resources.dll</SatelliteAssemblies>
     </PropertyGroup>
 
     <ZipFileCreateFromDirectory
@@ -22,14 +21,14 @@
         SourceDirectory="%(GenerateArchivesInputsOutputs.InputDirectory)"
         DestinationArchive="$(GenerateArchivesDestinationArchive)"
         OverwriteDestination="true"
-        ExcludePatterns="$(SatelliteAssemblies)" />
+        ExcludePatterns="%(GenerateArchivesInputsOutputs.ExcludePatterns)" />
 
     <TarGzFileCreateFromDirectory
         Condition=" '$(OSName)' != 'win' "
         SourceDirectory="%(GenerateArchivesInputsOutputs.InputDirectory)"
         DestinationArchive="$(GenerateArchivesDestinationArchive)"
         OverwriteDestination="true"
-        ExcludePatterns="$(SatelliteAssemblies)" />
+        ExcludePatterns="%(GenerateArchivesInputsOutputs.ExcludePatterns)" />
 
     <ItemGroup>
       <Archives Include="$(GenerateArchivesDestinationArchive)" />
@@ -45,6 +44,7 @@
         <Outputs>$(ArchiveOutputDirectory)/%(LayoutDefinition.NameWithVersion)$(ArchiveExtension)</Outputs>
         <InputDirectory>$(LayoutDirectory)/%(LayoutDefinition.Name)</InputDirectory>
         <OutFileName>%(LayoutDefinition.NameWithVersion)</OutFileName>
+        <ExcludePatterns>%(LayoutDefinition.ExcludePatterns)</ExcludePatterns>
       </GenerateArchivesInputsOutputs>
     </ItemGroup>
   </Target>

build/package/Layout.targets

@@ -3,6 +3,9 @@
   <PropertyGroup>
     <SdkDebugLayoutOutputDirectory>$(LayoutDirectory)/$(ArtifactNameSdkDebug)</SdkDebugLayoutOutputDirectory>
     <CombinedHostHostFxrFrameworkSdkOutputDirectory>$(LayoutDirectory)/$(ArtifactNameCombinedHostHostFxrFrameworkSdk)</CombinedHostHostFxrFrameworkSdkOutputDirectory>
+    <SdkLanguagePackOutputDirectory>$(LayoutDirectory)/$(ArtifactNameSdkLanguagePack)</SdkLanguagePackOutputDirectory>
+    <SatelliteAssemblies>*.resources.dll</SatelliteAssemblies>
+    <WindowsSatelliteAssembliesRegEx>.*.resources.dll</WindowsSatelliteAssembliesRegEx>
   </PropertyGroup>
 
   <Target DependsOnTargets="Init" Name="SetupLayoutInputsOutputs" >
@@ -11,6 +14,7 @@
       <SdkLayoutInput Include="$(OutputDirectory)/sdk/**/*" />
       <SdkDebugLayoutInput Include="$(SymbolsDirectory)/sdk/**/*" />
       <CombinedHostHostFxrFrameworkSdkInput Include="$(OutputDirectory)/**/*" />
+      <SdkLanguagePackInput Include="$(OutputDirectory)/sdk/**/$(SatelliteAssemblies)" />
 
       <AspNetRuntimeFilesInput Include="$(AspNetRuntimePackageStorePublishDirectory)/**/*" />
     </ItemGroup>
@@ -30,6 +34,11 @@
       Path2="%(CombinedHostHostFxrFrameworkSdkInput.Identity)" >
       <Output TaskParameter="RelativePath" ItemName="CombinedHostHostFxrFrameworkSdkRelativeOutputFiles" />
     </MakeRelative>
+    <MakeRelative
+      Path1="$(OutputDirectory)/"
+      Path2="%(SdkLanguagePackInput.Identity)" >
+      <Output TaskParameter="RelativePath" ItemName="SdkLanguagePackRelativeOutputFiles" />
+    </MakeRelative>
 
     <!-- Set up Items Defining Layouts for easy change -->
     <ItemGroup>
@@ -52,6 +61,15 @@
         <OutputFiles>@(CombinedHostHostFxrFrameworkSdkRelativeOutputFiles -> '$(CombinedHostHostFxrFrameworkSdkOutputDirectory)/%(Identity)')</OutputFiles>
         <NameWithVersion>$(ArtifactNameWithVersionCombinedHostHostFxrFrameworkSdk)</NameWithVersion>
         <Name>$(ArtifactNameCombinedHostHostFxrFrameworkSdk)</Name>
+        <ExcludePatterns Condition=" '$(OSName)' == 'win' ">$(WindowsSatelliteAssembliesRegEx)</ExcludePatterns>
+        <ExcludePatterns Condition=" '$(OSName)' != 'win' ">$(SatelliteAssemblies)</ExcludePatterns>
+      </LayoutDefinition>
+
+      <LayoutDefinition Include="SdkLanguagePack">
+        <InputFiles>@(SdkLanguagePackInput)</InputFiles>
+        <OutputFiles>@(SdkLanguagePackRelativeOutputFiles -> '$(SdkLanguagePackOutputDirectory)/%(Identity)')</OutputFiles>
+        <NameWithVersion>$(ArtifactNameWithVersionSdkLanguagePack)</NameWithVersion>
+        <Name>$(ArtifactNameSdkLanguagePack)</Name>
       </LayoutDefinition>
 
     </ItemGroup>