From 752599494fce80b5d0059a9090fdc010d8c7f45b Mon Sep 17 00:00:00 2001
From: Jonathan Miller <jonmill@microsoft.com>
Date: Tue, 1 Mar 2016 15:34:10 -0800
Subject: [PATCH] Adding builds files for the test projects

---
 build.proj                                    |  9 ++++-
 dir.props                                     |  4 +++
 dir.traversal.targets                         |  3 ++
 run-test.sh                                   | 17 ++++++++--
 src/Common/tests/Common.Tests.builds          | 13 +++++++
 .../tests/Microsoft.CSharp.Tests.builds       |  9 +++++
 .../pkg/Microsoft.VisualBasic.builds          |  4 ++-
 .../src/Microsoft.VisualBasic.builds          |  6 ++--
 .../tests/Microsoft.VisualBasic.Tests.builds  | 11 ++++++
 .../tests/Microsoft.VisualBasic.Tests.csproj  |  1 +
 .../Microsoft.Win32.Primitives.Tests.builds   | 17 ++++++++++
 ...rosoft.Win32.Registry.AccessControl.builds |  4 ++-
 ....Win32.Registry.AccessControl.Tests.builds | 11 ++++++
 .../Microsoft.Win32.Registry.Tests.builds     | 11 ++++++
 .../InterProcessCommunication.Tests.builds    | 10 ++++++
 .../tests/System.AppContext.Tests.builds      |  9 +++++
 .../tests/System.Buffers.Tests.builds         |  9 +++++
 ...System.Collections.Concurrent.Tests.builds |  9 +++++
 .../System.Collections.Immutable.Tests.builds |  9 +++++
 ...System.Collections.NonGeneric.Tests.builds |  9 +++++
 ...ystem.Collections.Specialized.Tests.builds |  9 +++++
 .../src/System.Collections.csproj             |  4 +--
 .../tests/System.Collections.Tests.builds     |  9 +++++
 .../tests/System.Collections.Tests.csproj     |  2 ++
 ...em.ComponentModel.Annotations.Tests.builds |  9 +++++
 ...omponentModel.EventBasedAsync.Tests.builds |  9 +++++
 ...tem.ComponentModel.Primitives.Tests.builds |  9 +++++
 ....ComponentModel.TypeConverter.Tests.builds |  9 +++++
 .../tests/System.ComponentModel.Tests.builds  |  9 +++++
 ...System.Composition.Convention.Tests.builds |  9 +++++
 .../tests/System.Composition.Tests.builds     |  8 +++++
 .../tests/System.Console.Tests.builds         |  9 +++++
 .../tests/System.Console.Tests.csproj         |  5 ++-
 .../tests/System.Data.Common.Tests.builds     |  9 +++++
 .../System.Data.SqlClient.Tests.csproj        |  1 +
 ....Data.SqlClient.ManualTesting.Tests.csproj |  1 +
 .../tests/System.Data.SqlClient.Tests.builds  |  9 +++++
 .../System.Diagnostics.Contracts.Tests.builds |  9 +++++
 .../System.Diagnostics.Debug.Tests.builds     | 20 +++++++++++
 ....Diagnostics.DiagnosticSource.Tests.builds |  9 +++++
 ...m.Diagnostics.FileVersionInfo.Tests.builds | 16 +++++++++
 .../System.Diagnostics.Process.Tests.builds   | 16 +++++++++
 ...stics.TextWriterTraceListener.Tests.builds |  9 +++++
 .../System.Diagnostics.Tools.Tests.builds     |  9 +++++
 ...ystem.Diagnostics.TraceSource.Tests.builds | 17 ++++++++++
 .../System.Diagnostics.Tracing.Tests.builds   |  9 +++++
 .../System.Drawing.Primitives.Tests.builds    |  9 +++++
 .../tests/System.Dynamic.Runtime.Tests.builds |  9 +++++
 ...ystem.Globalization.Calendars.Tests.builds |  9 +++++
 ...stem.Globalization.Extensions.Tests.builds | 14 ++++++++
 .../tests/System.Globalization.Tests.builds   |  9 +++++
 ...System.IO.Compression.ZipFile.Tests.builds |  9 +++++
 .../tests/System.IO.Compression.Tests.builds  | 17 ++++++++++
 .../System.IO.FileSystem.AccessControl.builds |  4 ++-
 ...m.IO.FileSystem.AccessControl.Tests.builds | 14 ++++++++
 ...ystem.IO.FileSystem.DriveInfo.Tests.builds | 20 +++++++++++
 ...ystem.IO.FileSystem.DriveInfo.Tests.csproj |  1 -
 ...stem.IO.FileSystem.Primitives.Tests.builds |  9 +++++
 .../System.IO.FileSystem.Watcher.Tests.builds | 17 ++++++++++
 .../tests/System.IO.FileSystem.Tests.builds   | 20 +++++++++++
 .../System.IO.MemoryMappedFiles.Tests.builds  | 17 ++++++++++
 .../tests/System.IO.Packaging.Tests.builds    |  9 +++++
 .../tests/System.IO.Pipes.Tests.builds        | 17 ++++++++++
 ...stem.IO.UnmanagedMemoryStream.Tests.builds |  9 +++++
 src/System.IO/src/System.IO.csproj            |  2 +-
 src/System.IO/tests/System.IO.Tests.builds    |  9 +++++
 src/System.IO/tests/System.IO.Tests.csproj    |  3 +-
 .../System.Linq.Expressions.Tests.builds      |  9 +++++
 .../tests/System.Linq.Parallel.Tests.builds   |  9 +++++
 .../tests/System.Linq.Queryable.Tests.builds  |  9 +++++
 .../tests/System.Linq.Tests.builds            |  9 +++++
 .../pkg/System.Net.Http.WinHttpHandler.builds |  4 ++-
 .../tests/System.Net.Http.Tests.builds        | 32 +++++++++++++++++
 .../System.Net.NameResolution.Tests.builds    | 19 +++++++++++
 ...System.Net.NetworkInformation.Tests.builds | 25 ++++++++++++++
 .../System.Net.Ping.Functional.Tests.builds   | 19 +++++++++++
 ...stem.Net.Primitives.UnitTests.Tests.builds | 34 +++++++++++++++++++
 .../tests/System.Net.Requests.Tests.builds    | 20 +++++++++++
 .../System.Net.Security.Unit.Tests.builds     | 25 ++++++++++++++
 .../src/System.Net.Sockets.csproj             |  2 +-
 .../System.Net.Sockets.Tests.csproj           |  3 --
 ...Net.Sockets.Async.Performance.Tests.csproj |  3 --
 .../tests/System.Net.Sockets.Tests.builds     | 26 ++++++++++++++
 ...ystem.Net.WebHeaderCollection.Tests.builds | 20 +++++++++++
 .../System.Net.WebSockets.Client.Tests.builds | 17 ++++++++++
 .../tests/System.Net.WebSockets.Tests.builds  |  9 +++++
 .../System.Numerics.Vectors.Tests.builds      |  9 +++++
 .../tests/System.ObjectModel.Tests.builds     |  9 +++++
 .../tests/System.Private.Uri.Tests.builds     | 13 +++++++
 .../tests/System.Private.Uri.Tests.csproj     | 14 ++------
 .../System.Reflection.Context.Tests.builds    | 11 ++++++
 .../System.Reflection.Context.Tests.csproj    |  1 +
 ...stem.Reflection.DispatchProxy.Tests.builds |  9 +++++
 ....Reflection.Emit.ILGeneration.Tests.builds |  9 +++++
 ...m.Reflection.Emit.Lightweight.Tests.builds |  9 +++++
 .../tests/System.Reflection.Emit.Tests.builds |  9 +++++
 .../System.Reflection.Extensions.Tests.builds |  9 +++++
 .../System.Reflection.Metadata.Tests.builds   |  9 +++++
 ...tem.Reflection.TypeExtensions.Tests.builds | 10 ++++++
 .../tests/System.Reflection.Tests.builds      | 10 ++++++
 .../System.Resources.Reader.Tests.builds      |  9 +++++
 ...System.Resources.ReaderWriter.Tests.builds |  9 +++++
 ...tem.Resources.ResourceManager.Tests.builds |  9 +++++
 .../System.Resources.Writer.Tests.builds      |  9 +++++
 .../System.Runtime.Extensions.Tests.builds    | 20 +++++++++++
 .../tests/System.Runtime.Handles.Tests.builds |  9 +++++
 ...ntime.InteropServices.PInvoke.Tests.builds |  9 +++++
 ...opServices.RuntimeInformation.Tests.builds | 20 +++++++++++
 ...ystem.Runtime.InteropServices.Tests.builds |  9 +++++
 ...ystem.Runtime.InteropServices.Tests.csproj |  3 --
 .../tests/System.Runtime.Loader.Tests.builds  | 10 ++++++
 .../System.Runtime.Numerics.Tests.builds      |  9 +++++
 ...em.Runtime.Serialization.Json.Tests.builds |  9 +++++
 ...tem.Runtime.Serialization.Xml.Tests.builds |  8 +++++
 .../tests/System.Runtime.Tests.builds         |  9 +++++
 .../tests/System.Runtime.Tests.csproj         |  4 +--
 .../pkg/System.Security.AccessControl.builds  |  4 ++-
 .../tests/System.Security.Claims.Tests.builds |  9 +++++
 ...urity.Cryptography.Algorithms.Tests.builds | 20 +++++++++++
 .../System.Security.Cryptography.Cng.builds   |  4 ++-
 ...tem.Security.Cryptography.Cng.Tests.builds | 11 ++++++
 .../System.Security.Cryptography.Csp.builds   |  4 ++-
 ...tem.Security.Cryptography.Csp.Tests.builds | 11 ++++++
 ...ecurity.Cryptography.Encoding.Tests.builds | 17 ++++++++++
 ...ystem.Security.Cryptography.OpenSsl.builds |  2 +-
 ...Security.Cryptography.OpenSsl.Tests.builds | 17 ++++++++++
 ...urity.Cryptography.Primitives.Tests.builds |  9 +++++
 ...Cryptography.X509Certificates.Tests.builds | 17 ++++++++++
 ...em.Security.Principal.Windows.Tests.builds | 11 ++++++
 .../System.Security.Principal.Tests.builds    | 11 ++++++
 ...ystem.Text.Encoding.CodePages.Tests.builds | 17 ++++++++++
 ...stem.Text.Encoding.Extensions.Tests.builds |  9 +++++
 .../tests/System.Text.Encoding.Tests.builds   |  9 +++++
 .../System.Text.Encodings.Web.Tests.builds    |  9 +++++
 ...ystem.Text.RegularExpressions.Tests.builds |  9 +++++
 ...ystem.Threading.AccessControl.Tests.builds | 11 ++++++
 ...ystem.Threading.AccessControl.Tests.csproj |  1 +
 .../System.Threading.Overlapped.Tests.builds  | 11 ++++++
 ...stem.Threading.Tasks.Dataflow.Tests.builds | 10 ++++++
 ...em.Threading.Tasks.Extensions.Tests.builds |  9 +++++
 ...stem.Threading.Tasks.Parallel.Tests.builds |  9 +++++
 .../src/System.Threading.Tasks.csproj         |  4 +--
 .../tests/System.Threading.Tasks.Tests.builds |  9 +++++
 .../tests/System.Threading.Tasks.Tests.csproj |  6 ----
 .../tests/System.Threading.Timer.Tests.builds |  9 +++++
 .../src/System.Threading.csproj               |  2 +-
 .../tests/System.Threading.Tests.builds       |  9 +++++
 .../tests/System.Threading.Tests.csproj       | 10 +-----
 .../System.Xml.ReaderWriter.Tests.builds      | 22 ++++++++++++
 .../tests/System.Xml.XDocument.Tests.builds   | 18 ++++++++++
 .../System.Xml.XPath.XDocument.Tests.builds   |  9 +++++
 .../System.Xml.XPath.XmlDocument.Tests.builds |  9 +++++
 .../tests/System.Xml.XPath.Tests.builds       |  9 +++++
 .../tests/System.Xml.XmlDocument.Tests.builds |  9 +++++
 .../System.Xml.XmlSerializer.Tests.builds     |  9 +++++
 src/tests.builds                              | 14 +++-----
 156 files changed, 1540 insertions(+), 75 deletions(-)
 create mode 100644 src/Common/tests/Common.Tests.builds
 create mode 100644 src/Microsoft.CSharp/tests/Microsoft.CSharp.Tests.builds
 create mode 100644 src/Microsoft.VisualBasic/tests/Microsoft.VisualBasic.Tests.builds
 create mode 100644 src/Microsoft.Win32.Primitives/tests/Microsoft.Win32.Primitives.Tests.builds
 create mode 100644 src/Microsoft.Win32.Registry.AccessControl/tests/Microsoft.Win32.Registry.AccessControl.Tests.builds
 create mode 100644 src/Microsoft.Win32.Registry/tests/Microsoft.Win32.Registry.Tests.builds
 create mode 100644 src/Scenarios/tests/InterProcessCommunication/InterProcessCommunication.Tests.builds
 create mode 100644 src/System.AppContext/tests/System.AppContext.Tests.builds
 create mode 100644 src/System.Buffers/tests/System.Buffers.Tests.builds
 create mode 100644 src/System.Collections.Concurrent/tests/System.Collections.Concurrent.Tests.builds
 create mode 100644 src/System.Collections.Immutable/tests/System.Collections.Immutable.Tests.builds
 create mode 100644 src/System.Collections.NonGeneric/tests/System.Collections.NonGeneric.Tests.builds
 create mode 100644 src/System.Collections.Specialized/tests/System.Collections.Specialized.Tests.builds
 create mode 100644 src/System.Collections/tests/System.Collections.Tests.builds
 create mode 100644 src/System.ComponentModel.Annotations/tests/System.ComponentModel.Annotations.Tests.builds
 create mode 100644 src/System.ComponentModel.EventBasedAsync/tests/System.ComponentModel.EventBasedAsync.Tests.builds
 create mode 100644 src/System.ComponentModel.Primitives/tests/System.ComponentModel.Primitives.Tests.builds
 create mode 100644 src/System.ComponentModel.TypeConverter/tests/System.ComponentModel.TypeConverter.Tests.builds
 create mode 100644 src/System.ComponentModel/tests/System.ComponentModel.Tests.builds
 create mode 100644 src/System.Composition.Convention/tests/System.Composition.Convention.Tests.builds
 create mode 100644 src/System.Composition/tests/System.Composition.Tests.builds
 create mode 100644 src/System.Console/tests/System.Console.Tests.builds
 create mode 100644 src/System.Data.Common/tests/System.Data.Common.Tests.builds
 create mode 100644 src/System.Data.SqlClient/tests/System.Data.SqlClient.Tests.builds
 create mode 100644 src/System.Diagnostics.Contracts/tests/System.Diagnostics.Contracts.Tests.builds
 create mode 100644 src/System.Diagnostics.Debug/tests/System.Diagnostics.Debug.Tests.builds
 create mode 100644 src/System.Diagnostics.DiagnosticSource/tests/System.Diagnostics.DiagnosticSource.Tests.builds
 create mode 100644 src/System.Diagnostics.FileVersionInfo/tests/System.Diagnostics.FileVersionInfo.Tests.builds
 create mode 100644 src/System.Diagnostics.Process/tests/System.Diagnostics.Process.Tests.builds
 create mode 100644 src/System.Diagnostics.TextWriterTraceListener/tests/System.Diagnostics.TextWriterTraceListener.Tests.builds
 create mode 100644 src/System.Diagnostics.Tools/tests/System.Diagnostics.Tools.Tests.builds
 create mode 100644 src/System.Diagnostics.TraceSource/tests/System.Diagnostics.TraceSource.Tests.builds
 create mode 100644 src/System.Diagnostics.Tracing/tests/System.Diagnostics.Tracing.Tests.builds
 create mode 100644 src/System.Drawing.Primitives/tests/System.Drawing.Primitives.Tests.builds
 create mode 100644 src/System.Dynamic.Runtime/tests/System.Dynamic.Runtime.Tests.builds
 create mode 100644 src/System.Globalization.Calendars/tests/System.Globalization.Calendars.Tests.builds
 create mode 100644 src/System.Globalization.Extensions/tests/System.Globalization.Extensions.Tests.builds
 create mode 100644 src/System.Globalization/tests/System.Globalization.Tests.builds
 create mode 100644 src/System.IO.Compression.ZipFile/tests/System.IO.Compression.ZipFile.Tests.builds
 create mode 100644 src/System.IO.Compression/tests/System.IO.Compression.Tests.builds
 create mode 100644 src/System.IO.FileSystem.AccessControl/tests/System.IO.FileSystem.AccessControl.Tests.builds
 create mode 100644 src/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.builds
 create mode 100644 src/System.IO.FileSystem.Primitives/tests/System.IO.FileSystem.Primitives.Tests.builds
 create mode 100644 src/System.IO.FileSystem.Watcher/tests/System.IO.FileSystem.Watcher.Tests.builds
 create mode 100644 src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.builds
 create mode 100644 src/System.IO.MemoryMappedFiles/tests/System.IO.MemoryMappedFiles.Tests.builds
 create mode 100644 src/System.IO.Packaging/tests/System.IO.Packaging.Tests.builds
 create mode 100644 src/System.IO.Pipes/tests/System.IO.Pipes.Tests.builds
 create mode 100644 src/System.IO.UnmanagedMemoryStream/tests/System.IO.UnmanagedMemoryStream.Tests.builds
 create mode 100644 src/System.IO/tests/System.IO.Tests.builds
 create mode 100644 src/System.Linq.Expressions/tests/System.Linq.Expressions.Tests.builds
 create mode 100644 src/System.Linq.Parallel/tests/System.Linq.Parallel.Tests.builds
 create mode 100644 src/System.Linq.Queryable/tests/System.Linq.Queryable.Tests.builds
 create mode 100644 src/System.Linq/tests/System.Linq.Tests.builds
 create mode 100644 src/System.Net.Http/tests/System.Net.Http.Tests.builds
 create mode 100644 src/System.Net.NameResolution/tests/System.Net.NameResolution.Tests.builds
 create mode 100644 src/System.Net.NetworkInformation/tests/System.Net.NetworkInformation.Tests.builds
 create mode 100644 src/System.Net.Ping/tests/System.Net.Ping.Functional.Tests.builds
 create mode 100644 src/System.Net.Primitives/tests/System.Net.Primitives.UnitTests.Tests.builds
 create mode 100644 src/System.Net.Requests/tests/System.Net.Requests.Tests.builds
 create mode 100644 src/System.Net.Security/tests/System.Net.Security.Unit.Tests.builds
 create mode 100644 src/System.Net.Sockets/tests/System.Net.Sockets.Tests.builds
 create mode 100644 src/System.Net.WebHeaderCollection/tests/System.Net.WebHeaderCollection.Tests.builds
 create mode 100644 src/System.Net.WebSockets.Client/tests/System.Net.WebSockets.Client.Tests.builds
 create mode 100644 src/System.Net.WebSockets/tests/System.Net.WebSockets.Tests.builds
 create mode 100644 src/System.Numerics.Vectors/tests/System.Numerics.Vectors.Tests.builds
 create mode 100644 src/System.ObjectModel/tests/System.ObjectModel.Tests.builds
 create mode 100644 src/System.Private.Uri/tests/System.Private.Uri.Tests.builds
 create mode 100644 src/System.Reflection.Context/tests/System.Reflection.Context.Tests.builds
 create mode 100644 src/System.Reflection.DispatchProxy/tests/System.Reflection.DispatchProxy.Tests.builds
 create mode 100644 src/System.Reflection.Emit.ILGeneration/tests/System.Reflection.Emit.ILGeneration.Tests.builds
 create mode 100644 src/System.Reflection.Emit.Lightweight/tests/System.Reflection.Emit.Lightweight.Tests.builds
 create mode 100644 src/System.Reflection.Emit/tests/System.Reflection.Emit.Tests.builds
 create mode 100644 src/System.Reflection.Extensions/tests/System.Reflection.Extensions.Tests.builds
 create mode 100644 src/System.Reflection.Metadata/tests/System.Reflection.Metadata.Tests.builds
 create mode 100644 src/System.Reflection.TypeExtensions/tests/System.Reflection.TypeExtensions.Tests.builds
 create mode 100644 src/System.Reflection/tests/System.Reflection.Tests.builds
 create mode 100644 src/System.Resources.Reader/tests/System.Resources.Reader.Tests.builds
 create mode 100644 src/System.Resources.ReaderWriter/tests/System.Resources.ReaderWriter.Tests.builds
 create mode 100644 src/System.Resources.ResourceManager/tests/System.Resources.ResourceManager.Tests.builds
 create mode 100644 src/System.Resources.Writer/tests/System.Resources.Writer.Tests.builds
 create mode 100644 src/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.builds
 create mode 100644 src/System.Runtime.Handles/tests/System.Runtime.Handles.Tests.builds
 create mode 100644 src/System.Runtime.InteropServices.PInvoke/tests/System.Runtime.InteropServices.PInvoke.Tests.builds
 create mode 100644 src/System.Runtime.InteropServices.RuntimeInformation/tests/System.Runtime.InteropServices.RuntimeInformation.Tests.builds
 create mode 100644 src/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.Tests.builds
 create mode 100644 src/System.Runtime.Loader/tests/System.Runtime.Loader.Tests.builds
 create mode 100644 src/System.Runtime.Numerics/tests/System.Runtime.Numerics.Tests.builds
 create mode 100644 src/System.Runtime.Serialization.Json/tests/System.Runtime.Serialization.Json.Tests.builds
 create mode 100644 src/System.Runtime.Serialization.Xml/tests/System.Runtime.Serialization.Xml.Tests.builds
 create mode 100644 src/System.Runtime/tests/System.Runtime.Tests.builds
 create mode 100644 src/System.Security.Claims/tests/System.Security.Claims.Tests.builds
 create mode 100644 src/System.Security.Cryptography.Algorithms/tests/System.Security.Cryptography.Algorithms.Tests.builds
 create mode 100644 src/System.Security.Cryptography.Cng/tests/System.Security.Cryptography.Cng.Tests.builds
 create mode 100644 src/System.Security.Cryptography.Csp/tests/System.Security.Cryptography.Csp.Tests.builds
 create mode 100644 src/System.Security.Cryptography.Encoding/tests/System.Security.Cryptography.Encoding.Tests.builds
 create mode 100644 src/System.Security.Cryptography.OpenSsl/tests/System.Security.Cryptography.OpenSsl.Tests.builds
 create mode 100644 src/System.Security.Cryptography.Primitives/tests/System.Security.Cryptography.Primitives.Tests.builds
 create mode 100644 src/System.Security.Cryptography.X509Certificates/tests/System.Security.Cryptography.X509Certificates.Tests.builds
 create mode 100644 src/System.Security.Principal.Windows/tests/System.Security.Principal.Windows.Tests.builds
 create mode 100644 src/System.Security.Principal/tests/System.Security.Principal.Tests.builds
 create mode 100644 src/System.Text.Encoding.CodePages/tests/System.Text.Encoding.CodePages.Tests.builds
 create mode 100644 src/System.Text.Encoding.Extensions/tests/System.Text.Encoding.Extensions.Tests.builds
 create mode 100644 src/System.Text.Encoding/tests/System.Text.Encoding.Tests.builds
 create mode 100644 src/System.Text.Encodings.Web/tests/System.Text.Encodings.Web.Tests.builds
 create mode 100644 src/System.Text.RegularExpressions/tests/System.Text.RegularExpressions.Tests.builds
 create mode 100644 src/System.Threading.AccessControl/tests/System.Threading.AccessControl.Tests.builds
 create mode 100644 src/System.Threading.Overlapped/tests/System.Threading.Overlapped.Tests.builds
 create mode 100644 src/System.Threading.Tasks.Dataflow/tests/System.Threading.Tasks.Dataflow.Tests.builds
 create mode 100644 src/System.Threading.Tasks.Extensions/tests/System.Threading.Tasks.Extensions.Tests.builds
 create mode 100644 src/System.Threading.Tasks.Parallel/tests/System.Threading.Tasks.Parallel.Tests.builds
 create mode 100644 src/System.Threading.Tasks/tests/System.Threading.Tasks.Tests.builds
 create mode 100644 src/System.Threading.Timer/tests/System.Threading.Timer.Tests.builds
 create mode 100644 src/System.Threading/tests/System.Threading.Tests.builds
 create mode 100644 src/System.Xml.ReaderWriter/tests/System.Xml.ReaderWriter.Tests.builds
 create mode 100644 src/System.Xml.XDocument/tests/System.Xml.XDocument.Tests.builds
 create mode 100644 src/System.Xml.XPath.XDocument/tests/System.Xml.XPath.XDocument.Tests.builds
 create mode 100644 src/System.Xml.XPath.XmlDocument/tests/System.Xml.XPath.XmlDocument.Tests.builds
 create mode 100644 src/System.Xml.XPath/tests/System.Xml.XPath.Tests.builds
 create mode 100644 src/System.Xml.XmlDocument/tests/System.Xml.XmlDocument.Tests.builds
 create mode 100644 src/System.Xml.XmlSerializer/tests/System.Xml.XmlSerializer.Tests.builds

diff --git a/build.proj b/build.proj
index 331291a053d3..c0a880806ed3 100644
--- a/build.proj
+++ b/build.proj
@@ -4,6 +4,10 @@
     <!-- Capture OSGroup passed to command line for setting default FilterToOSGroup value below -->
     <_OriginalOSGroup>$(OSGroup)</_OriginalOSGroup>
   </PropertyGroup>
+  <PropertyGroup>
+    <InputOSGroup>$(OSGroup)</InputOSGroup>
+    <InputOSGroup Condition="'$(InputOSGroup)'==''">$(FilterToOSGroup)</InputOSGroup>
+  </PropertyGroup>
   <Import Project="dir.props" />
 
   <!-- required to build the projects in their specified order -->
@@ -25,8 +29,11 @@
     <Project Include="src\dirs.proj">
       <!-- For the root traversal default filter the OSGroup to the OSEnvironment which is the OS we are running on -->
       <FilterToOSGroup Condition="'$(_OriginalOSGroup)' == ''">$(OSEnvironment)</FilterToOSGroup>
+      <InputOSGroup>$(InputOSGroup)</InputOSGroup>
+    </Project>
+    <Project Include="src\tests.builds" Condition="$(BuildTests)=='true'">
+      <InputOSGroup>$(InputOSGroup)</InputOSGroup>
     </Project>
-    <Project Include="src\tests.builds" Condition="$(BuildTests)=='true'"/>
     <!-- signing must happen before packaging -->
     <Project Include="src\sign.builds" />
     <Project Include="src\packages.builds" Condition="'$(BuildPackages)'=='true'"/>
diff --git a/dir.props b/dir.props
index 214215643422..910e597ecad8 100644
--- a/dir.props
+++ b/dir.props
@@ -11,6 +11,10 @@
     <OsEnvironment Condition="'$(OsEnvironment)'==''">$(OS)</OsEnvironment>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <InputOSGroup Condition="'$(InputOSGroup)'==''">$(OSEnvironment)</InputOSGroup>
+  </PropertyGroup>
+
   <!-- Build Tools Versions -->
   <PropertyGroup>
     <RoslynVersion>1.0.0-rc3-20150510-01</RoslynVersion>
diff --git a/dir.traversal.targets b/dir.traversal.targets
index cfd6e2e61921..0c56c0679ceb 100644
--- a/dir.traversal.targets
+++ b/dir.traversal.targets
@@ -22,6 +22,9 @@
       <Project>
         <AdditionalProperties Condition="'%(Project.FilterToOSGroup)'!=''">FilterToOSGroup=%(Project.FilterToOSGroup);%(Project.AdditionalProperties)</AdditionalProperties>
       </Project>
+      <Project>
+        <AdditionalProperties Condition="'%(Project.InputOSGroup)' != ''">InputOSGroup=%(Project.InputOSGroup);%(Project.AdditionalProperties)</AdditionalProperties>
+      </Project>
       <Project>
         <!-- If a project isn't setting the OSGroup via metadata then undefine it so that the globally set OSGroup doesn't override empty OSGroup -->
         <UndefineProperties Condition="'%(Project.OSGroup)'==''">%(Project.UndefineProperties);OSGroup</UndefineProperties>
diff --git a/run-test.sh b/run-test.sh
index 3bd4fa1be1de..b25d773446fc 100755
--- a/run-test.sh
+++ b/run-test.sh
@@ -83,7 +83,6 @@ esac
 # Misc defaults
 TestSelection=".*"
 TestsFailed=0
-OverlayDir="$ProjectRoot/bin/tests/$OS.AnyCPU.$ConfigurationGroup/TestOverlay/"
 
 create_test_overlay()
 {
@@ -163,8 +162,16 @@ runtest()
 
   if [ ! -d "$dirName" ] || [ ! -f "$dirName/$testDllName" ]
   then
-    echo "error: Did not find corresponding test dll for $testProject at $dirName/$testDllName"
-    exit 1
+    dirName="$AnyOsTestDir/$fileNameWithoutExtension/dnxcore50"
+    if [ ! -d "$dirName" ] || [ ! -f "$dirName/$testDllName" ]
+    then
+      dirName="$UnixTestDir/$fileNameWithoutExtension/dnxcore50"
+      if [ ! -d "$dirName" ] || [ ! -f "$dirName/$testDllName" ]
+      then
+        echo "error: Did not find corresponding test dll for $testProject"
+        exit 1
+      fi
+    fi
   fi
 
   copy_test_overlay $dirName
@@ -303,6 +310,10 @@ do
     shift
 done
 
+OverlayDir="$ProjectRoot/bin/tests/$OS.AnyCPU.$ConfigurationGroup/TestOverlay/"
+AnyOsTestDir="$ProjectRoot/bin/tests/AnyOS.AnyCPU.$ConfigurationGroup"
+UnixTestDir="$ProjectRoot/bin/tests/Unix.AnyCPU.$ConfigurationGroup"
+
 # Compute paths to the binaries if they haven't already been computed
 
 if [ "$CoreClrBins" == "" ]
diff --git a/src/Common/tests/Common.Tests.builds b/src/Common/tests/Common.Tests.builds
new file mode 100644
index 000000000000..89484b497c05
--- /dev/null
+++ b/src/Common/tests/Common.Tests.builds
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="Common.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+    <Project Include="Common.Tests.csproj">
+      <OSGroup>Unix</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/Microsoft.CSharp/tests/Microsoft.CSharp.Tests.builds b/src/Microsoft.CSharp/tests/Microsoft.CSharp.Tests.builds
new file mode 100644
index 000000000000..93bd833b6679
--- /dev/null
+++ b/src/Microsoft.CSharp/tests/Microsoft.CSharp.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="Microsoft.CSharp.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/Microsoft.VisualBasic/pkg/Microsoft.VisualBasic.builds b/src/Microsoft.VisualBasic/pkg/Microsoft.VisualBasic.builds
index fcbbed749ebe..2425d0ec96cb 100644
--- a/src/Microsoft.VisualBasic/pkg/Microsoft.VisualBasic.builds
+++ b/src/Microsoft.VisualBasic/pkg/Microsoft.VisualBasic.builds
@@ -3,7 +3,9 @@
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <ItemGroup>
     <!-- Temporary workaround, VisualBasic projects cannot be built on non-Windows platforms. See issue #5230. -->
-    <Project Include="Microsoft.VisualBasic.pkgproj" Condition="'$(OSEnvironment)' == 'Windows_NT'" />
+    <Project Include="Microsoft.VisualBasic.pkgproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
 </Project>
diff --git a/src/Microsoft.VisualBasic/src/Microsoft.VisualBasic.builds b/src/Microsoft.VisualBasic/src/Microsoft.VisualBasic.builds
index 6a7ae8e9f771..c50e4482d93a 100644
--- a/src/Microsoft.VisualBasic/src/Microsoft.VisualBasic.builds
+++ b/src/Microsoft.VisualBasic/src/Microsoft.VisualBasic.builds
@@ -3,7 +3,9 @@
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <ItemGroup>
     <!-- Temporary workaround, VisualBasic projects cannot be built on non-Windows platforms. See issue #5230. -->
-    <Project Include="Microsoft.VisualBasic.vbproj" Condition="'$(OSEnvironment)' == 'Windows_NT'" />
+    <Project Include="Microsoft.VisualBasic.vbproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/Microsoft.VisualBasic/tests/Microsoft.VisualBasic.Tests.builds b/src/Microsoft.VisualBasic/tests/Microsoft.VisualBasic.Tests.builds
new file mode 100644
index 000000000000..8aa48a5dcd75
--- /dev/null
+++ b/src/Microsoft.VisualBasic/tests/Microsoft.VisualBasic.Tests.builds
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <!-- Temporary workaround, VisualBasic projects cannot be built on non-Windows platforms. See issue #5230. -->
+    <Project Include="Microsoft.VisualBasic.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/Microsoft.VisualBasic/tests/Microsoft.VisualBasic.Tests.csproj b/src/Microsoft.VisualBasic/tests/Microsoft.VisualBasic.Tests.csproj
index a3860027598a..986465660a78 100644
--- a/src/Microsoft.VisualBasic/tests/Microsoft.VisualBasic.Tests.csproj
+++ b/src/Microsoft.VisualBasic/tests/Microsoft.VisualBasic.Tests.csproj
@@ -5,6 +5,7 @@
     <ProjectGuid>{82B54697-0251-47A1-8546-FC507D0F3B08}</ProjectGuid>
     <AssemblyName>Microsoft.VisualBasic.Tests</AssemblyName>
     <RootNamespace>Microsoft.VisualBasic.Tests</RootNamespace>
+    <UnsupportedPlatforms>Linux;NetBSD;OSX</UnsupportedPlatforms>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|AnyCPU'" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|AnyCPU'" />
diff --git a/src/Microsoft.Win32.Primitives/tests/Microsoft.Win32.Primitives.Tests.builds b/src/Microsoft.Win32.Primitives/tests/Microsoft.Win32.Primitives.Tests.builds
new file mode 100644
index 000000000000..64be5940e0e9
--- /dev/null
+++ b/src/Microsoft.Win32.Primitives/tests/Microsoft.Win32.Primitives.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="Microsoft.Win32.Primitives.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="Microsoft.Win32.Primitives.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="Microsoft.Win32.Primitives.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/Microsoft.Win32.Registry.AccessControl/pkg/Microsoft.Win32.Registry.AccessControl.builds b/src/Microsoft.Win32.Registry.AccessControl/pkg/Microsoft.Win32.Registry.AccessControl.builds
index c3bc001dcc37..95bff1126212 100644
--- a/src/Microsoft.Win32.Registry.AccessControl/pkg/Microsoft.Win32.Registry.AccessControl.builds
+++ b/src/Microsoft.Win32.Registry.AccessControl/pkg/Microsoft.Win32.Registry.AccessControl.builds
@@ -2,7 +2,9 @@
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <ItemGroup>
-    <Project Include="Microsoft.Win32.Registry.AccessControl.pkgproj" />
+    <Project Include="Microsoft.Win32.Registry.AccessControl.pkgproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
 </Project>
diff --git a/src/Microsoft.Win32.Registry.AccessControl/tests/Microsoft.Win32.Registry.AccessControl.Tests.builds b/src/Microsoft.Win32.Registry.AccessControl/tests/Microsoft.Win32.Registry.AccessControl.Tests.builds
new file mode 100644
index 000000000000..62209136db5b
--- /dev/null
+++ b/src/Microsoft.Win32.Registry.AccessControl/tests/Microsoft.Win32.Registry.AccessControl.Tests.builds
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="Microsoft.Win32.Registry.AccessControl.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/Microsoft.Win32.Registry/tests/Microsoft.Win32.Registry.Tests.builds b/src/Microsoft.Win32.Registry/tests/Microsoft.Win32.Registry.Tests.builds
new file mode 100644
index 000000000000..200b5fe9415b
--- /dev/null
+++ b/src/Microsoft.Win32.Registry/tests/Microsoft.Win32.Registry.Tests.builds
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="Microsoft.Win32.Registry.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/Scenarios/tests/InterProcessCommunication/InterProcessCommunication.Tests.builds b/src/Scenarios/tests/InterProcessCommunication/InterProcessCommunication.Tests.builds
new file mode 100644
index 000000000000..c579d04e6982
--- /dev/null
+++ b/src/Scenarios/tests/InterProcessCommunication/InterProcessCommunication.Tests.builds
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="InterProcessCommunication.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.AppContext/tests/System.AppContext.Tests.builds b/src/System.AppContext/tests/System.AppContext.Tests.builds
new file mode 100644
index 000000000000..4b5268e5b11d
--- /dev/null
+++ b/src/System.AppContext/tests/System.AppContext.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.AppContext.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Buffers/tests/System.Buffers.Tests.builds b/src/System.Buffers/tests/System.Buffers.Tests.builds
new file mode 100644
index 000000000000..8d89d890d7cb
--- /dev/null
+++ b/src/System.Buffers/tests/System.Buffers.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Buffers.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Collections.Concurrent/tests/System.Collections.Concurrent.Tests.builds b/src/System.Collections.Concurrent/tests/System.Collections.Concurrent.Tests.builds
new file mode 100644
index 000000000000..236df79da95f
--- /dev/null
+++ b/src/System.Collections.Concurrent/tests/System.Collections.Concurrent.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Collections.Concurrent.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Collections.Immutable/tests/System.Collections.Immutable.Tests.builds b/src/System.Collections.Immutable/tests/System.Collections.Immutable.Tests.builds
new file mode 100644
index 000000000000..4322f59987f1
--- /dev/null
+++ b/src/System.Collections.Immutable/tests/System.Collections.Immutable.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Collections.Immutable.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Collections.NonGeneric/tests/System.Collections.NonGeneric.Tests.builds b/src/System.Collections.NonGeneric/tests/System.Collections.NonGeneric.Tests.builds
new file mode 100644
index 000000000000..ce9f85e3514f
--- /dev/null
+++ b/src/System.Collections.NonGeneric/tests/System.Collections.NonGeneric.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Collections.NonGeneric.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Collections.Specialized/tests/System.Collections.Specialized.Tests.builds b/src/System.Collections.Specialized/tests/System.Collections.Specialized.Tests.builds
new file mode 100644
index 000000000000..5560a26b15b4
--- /dev/null
+++ b/src/System.Collections.Specialized/tests/System.Collections.Specialized.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Collections.Specialized.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Collections/src/System.Collections.csproj b/src/System.Collections/src/System.Collections.csproj
index 34837bbb0704..25ca70a63808 100644
--- a/src/System.Collections/src/System.Collections.csproj
+++ b/src/System.Collections/src/System.Collections.csproj
@@ -20,8 +20,8 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'netcore50aotao_Release|AnyCPU'" />
   <ItemGroup Condition="'$(TargetGroup)' == ''">
     <ProjectReference Include="..\..\System.Runtime\src\System.Runtime.csproj" />
-    <ProjectReference Include="..\..\System.Diagnostics.Debug\src\System.Diagnostics.Debug.csproj">
-      <OSGroup>Windows_NT</OSGroup>
+    <ProjectReference Include="..\..\System.Diagnostics.Debug\src\System.Diagnostics.Debug.csproj" >
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
   </ItemGroup>
   <ItemGroup Condition="'$(TargetGroup)' != 'net46'">
diff --git a/src/System.Collections/tests/System.Collections.Tests.builds b/src/System.Collections/tests/System.Collections.Tests.builds
new file mode 100644
index 000000000000..2efac79eb1ba
--- /dev/null
+++ b/src/System.Collections/tests/System.Collections.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Collections.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Collections/tests/System.Collections.Tests.csproj b/src/System.Collections/tests/System.Collections.Tests.csproj
index f957ca47efb3..d009d4d0f56d 100644
--- a/src/System.Collections/tests/System.Collections.Tests.csproj
+++ b/src/System.Collections/tests/System.Collections.Tests.csproj
@@ -22,6 +22,7 @@
       <OutputItemType>Content</OutputItemType>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
       <Targets>Build;DebugSymbolsProjectOutputGroup</Targets>
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
     <ProjectReference Include="..\..\System.Runtime\src\System.Runtime.csproj">
       <ReferenceOutputAssembly>false</ReferenceOutputAssembly>
@@ -34,6 +35,7 @@
       <OutputItemType>Content</OutputItemType>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
       <Targets>Build;DebugSymbolsProjectOutputGroup</Targets>
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
diff --git a/src/System.ComponentModel.Annotations/tests/System.ComponentModel.Annotations.Tests.builds b/src/System.ComponentModel.Annotations/tests/System.ComponentModel.Annotations.Tests.builds
new file mode 100644
index 000000000000..34d0b4dde2d1
--- /dev/null
+++ b/src/System.ComponentModel.Annotations/tests/System.ComponentModel.Annotations.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.ComponentModel.Annotations.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.ComponentModel.EventBasedAsync/tests/System.ComponentModel.EventBasedAsync.Tests.builds b/src/System.ComponentModel.EventBasedAsync/tests/System.ComponentModel.EventBasedAsync.Tests.builds
new file mode 100644
index 000000000000..1fb88003df3c
--- /dev/null
+++ b/src/System.ComponentModel.EventBasedAsync/tests/System.ComponentModel.EventBasedAsync.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.ComponentModel.EventBasedAsync.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.ComponentModel.Primitives/tests/System.ComponentModel.Primitives.Tests.builds b/src/System.ComponentModel.Primitives/tests/System.ComponentModel.Primitives.Tests.builds
new file mode 100644
index 000000000000..83e1092e1a4f
--- /dev/null
+++ b/src/System.ComponentModel.Primitives/tests/System.ComponentModel.Primitives.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.ComponentModel.Primitives.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.ComponentModel.TypeConverter/tests/System.ComponentModel.TypeConverter.Tests.builds b/src/System.ComponentModel.TypeConverter/tests/System.ComponentModel.TypeConverter.Tests.builds
new file mode 100644
index 000000000000..41ec5eeaad45
--- /dev/null
+++ b/src/System.ComponentModel.TypeConverter/tests/System.ComponentModel.TypeConverter.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.ComponentModel.TypeConverter.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.ComponentModel/tests/System.ComponentModel.Tests.builds b/src/System.ComponentModel/tests/System.ComponentModel.Tests.builds
new file mode 100644
index 000000000000..223dc68d8947
--- /dev/null
+++ b/src/System.ComponentModel/tests/System.ComponentModel.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.ComponentModel.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Composition.Convention/tests/System.Composition.Convention.Tests.builds b/src/System.Composition.Convention/tests/System.Composition.Convention.Tests.builds
new file mode 100644
index 000000000000..925498c8881e
--- /dev/null
+++ b/src/System.Composition.Convention/tests/System.Composition.Convention.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Composition.Convention.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Composition/tests/System.Composition.Tests.builds b/src/System.Composition/tests/System.Composition.Tests.builds
new file mode 100644
index 000000000000..656c42e66f0c
--- /dev/null
+++ b/src/System.Composition/tests/System.Composition.Tests.builds
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Composition.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Console/tests/System.Console.Tests.builds b/src/System.Console/tests/System.Console.Tests.builds
new file mode 100644
index 000000000000..fa97b971083c
--- /dev/null
+++ b/src/System.Console/tests/System.Console.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Console.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Console/tests/System.Console.Tests.csproj b/src/System.Console/tests/System.Console.Tests.csproj
index 3ce4afd46845..b7768ca10639 100644
--- a/src/System.Console/tests/System.Console.Tests.csproj
+++ b/src/System.Console/tests/System.Console.Tests.csproj
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
-    <Configuration Condition="'$(Configuration)'==''">Windows_Debug</Configuration>
-  </PropertyGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -61,10 +58,12 @@
     <ProjectReference Include="..\src\System.Console.csproj">
       <Project>{F9DF2357-81B4-4317-908E-512DA9395583}</Project>
       <Name>System.Console</Name>
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
     <ProjectReference Include="$(CommonTestPath)\System\Diagnostics\RemoteExecutorConsoleApp\RemoteExecutorConsoleApp.csproj">
       <Project>{69e46a6f-9966-45a5-8945-2559fe337827}</Project>
       <Name>RemoteExecutorConsoleApp</Name>
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
diff --git a/src/System.Data.Common/tests/System.Data.Common.Tests.builds b/src/System.Data.Common/tests/System.Data.Common.Tests.builds
new file mode 100644
index 000000000000..db3c12c00cff
--- /dev/null
+++ b/src/System.Data.Common/tests/System.Data.Common.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Data.Common.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Data.SqlClient/tests/FunctionalTests/System.Data.SqlClient.Tests.csproj b/src/System.Data.SqlClient/tests/FunctionalTests/System.Data.SqlClient.Tests.csproj
index 921235a36815..0e912d6a266c 100644
--- a/src/System.Data.SqlClient/tests/FunctionalTests/System.Data.SqlClient.Tests.csproj
+++ b/src/System.Data.SqlClient/tests/FunctionalTests/System.Data.SqlClient.Tests.csproj
@@ -9,6 +9,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>System.Data.SqlClient.Tests</RootNamespace>
     <AssemblyName>System.Data.SqlClient.Tests</AssemblyName>
+    <UnsupportedPlatforms>Linux;OSX</UnsupportedPlatforms>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Linux_Debug|AnyCPU'" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Linux_Release|AnyCPU'" />
diff --git a/src/System.Data.SqlClient/tests/ManualTests/System.Data.SqlClient.ManualTesting.Tests.csproj b/src/System.Data.SqlClient/tests/ManualTests/System.Data.SqlClient.ManualTesting.Tests.csproj
index 2a2a37955a00..0ee1e341f8ef 100644
--- a/src/System.Data.SqlClient/tests/ManualTests/System.Data.SqlClient.ManualTesting.Tests.csproj
+++ b/src/System.Data.SqlClient/tests/ManualTests/System.Data.SqlClient.ManualTesting.Tests.csproj
@@ -14,6 +14,7 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Windows_Release|AnyCPU'" />
   <PropertyGroup Condition=" '$(TargetsWindows)' != 'true' ">
     <DefineConstants>$(DefineConstants);MANAGED_SNI</DefineConstants>
+    <UnsupportedPlatforms>Linux;OSX</UnsupportedPlatforms>
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\src\System.Data.SqlClient.csproj">
diff --git a/src/System.Data.SqlClient/tests/System.Data.SqlClient.Tests.builds b/src/System.Data.SqlClient/tests/System.Data.SqlClient.Tests.builds
new file mode 100644
index 000000000000..c3a40f719d14
--- /dev/null
+++ b/src/System.Data.SqlClient/tests/System.Data.SqlClient.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="FunctionalTests\System.Data.SqlClient.Tests.csproj" />
+    <Project Include="ManualTests\System.Data.SqlClient.ManualTesting.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Diagnostics.Contracts/tests/System.Diagnostics.Contracts.Tests.builds b/src/System.Diagnostics.Contracts/tests/System.Diagnostics.Contracts.Tests.builds
new file mode 100644
index 000000000000..90a06d485c0e
--- /dev/null
+++ b/src/System.Diagnostics.Contracts/tests/System.Diagnostics.Contracts.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Diagnostics.Contracts.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Diagnostics.Debug/tests/System.Diagnostics.Debug.Tests.builds b/src/System.Diagnostics.Debug/tests/System.Diagnostics.Debug.Tests.builds
new file mode 100644
index 000000000000..c36efce3d8e2
--- /dev/null
+++ b/src/System.Diagnostics.Debug/tests/System.Diagnostics.Debug.Tests.builds
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Diagnostics.Debug.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="System.Diagnostics.Debug.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Diagnostics.Debug.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Diagnostics.Debug.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Diagnostics.DiagnosticSource/tests/System.Diagnostics.DiagnosticSource.Tests.builds b/src/System.Diagnostics.DiagnosticSource/tests/System.Diagnostics.DiagnosticSource.Tests.builds
new file mode 100644
index 000000000000..ce2c3e28c1fa
--- /dev/null
+++ b/src/System.Diagnostics.DiagnosticSource/tests/System.Diagnostics.DiagnosticSource.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Diagnostics.DiagnosticSource.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Diagnostics.FileVersionInfo/tests/System.Diagnostics.FileVersionInfo.Tests.builds b/src/System.Diagnostics.FileVersionInfo/tests/System.Diagnostics.FileVersionInfo.Tests.builds
new file mode 100644
index 000000000000..f28755894574
--- /dev/null
+++ b/src/System.Diagnostics.FileVersionInfo/tests/System.Diagnostics.FileVersionInfo.Tests.builds
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Diagnostics.FileVersionInfo.Tests\System.Diagnostics.FileVersionInfo.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Diagnostics.FileVersionInfo.Tests\System.Diagnostics.FileVersionInfo.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Diagnostics.FileVersionInfo.Tests\System.Diagnostics.FileVersionInfo.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Diagnostics.Process/tests/System.Diagnostics.Process.Tests.builds b/src/System.Diagnostics.Process/tests/System.Diagnostics.Process.Tests.builds
new file mode 100644
index 000000000000..85dcb47ddfc4
--- /dev/null
+++ b/src/System.Diagnostics.Process/tests/System.Diagnostics.Process.Tests.builds
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Diagnostics.Process.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Diagnostics.Process.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Diagnostics.Process.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Diagnostics.TextWriterTraceListener/tests/System.Diagnostics.TextWriterTraceListener.Tests.builds b/src/System.Diagnostics.TextWriterTraceListener/tests/System.Diagnostics.TextWriterTraceListener.Tests.builds
new file mode 100644
index 000000000000..c3fcc7162551
--- /dev/null
+++ b/src/System.Diagnostics.TextWriterTraceListener/tests/System.Diagnostics.TextWriterTraceListener.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Diagnostics.TextWriterTraceListener.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Diagnostics.Tools/tests/System.Diagnostics.Tools.Tests.builds b/src/System.Diagnostics.Tools/tests/System.Diagnostics.Tools.Tests.builds
new file mode 100644
index 000000000000..8db8171a76bc
--- /dev/null
+++ b/src/System.Diagnostics.Tools/tests/System.Diagnostics.Tools.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Diagnostics.Tools.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Diagnostics.TraceSource/tests/System.Diagnostics.TraceSource.Tests.builds b/src/System.Diagnostics.TraceSource/tests/System.Diagnostics.TraceSource.Tests.builds
new file mode 100644
index 000000000000..0afffc859842
--- /dev/null
+++ b/src/System.Diagnostics.TraceSource/tests/System.Diagnostics.TraceSource.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Diagnostics.TraceSource.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Diagnostics.TraceSource.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Diagnostics.TraceSource.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Diagnostics.Tracing/tests/System.Diagnostics.Tracing.Tests.builds b/src/System.Diagnostics.Tracing/tests/System.Diagnostics.Tracing.Tests.builds
new file mode 100644
index 000000000000..fd4743f6d645
--- /dev/null
+++ b/src/System.Diagnostics.Tracing/tests/System.Diagnostics.Tracing.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Diagnostics.Tracing.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Drawing.Primitives/tests/System.Drawing.Primitives.Tests.builds b/src/System.Drawing.Primitives/tests/System.Drawing.Primitives.Tests.builds
new file mode 100644
index 000000000000..694957532123
--- /dev/null
+++ b/src/System.Drawing.Primitives/tests/System.Drawing.Primitives.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Drawing.Primitives.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Dynamic.Runtime/tests/System.Dynamic.Runtime.Tests.builds b/src/System.Dynamic.Runtime/tests/System.Dynamic.Runtime.Tests.builds
new file mode 100644
index 000000000000..1c923e24d8a8
--- /dev/null
+++ b/src/System.Dynamic.Runtime/tests/System.Dynamic.Runtime.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Dynamic.Runtime.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Globalization.Calendars/tests/System.Globalization.Calendars.Tests.builds b/src/System.Globalization.Calendars/tests/System.Globalization.Calendars.Tests.builds
new file mode 100644
index 000000000000..eba3f1737bc3
--- /dev/null
+++ b/src/System.Globalization.Calendars/tests/System.Globalization.Calendars.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Globalization.Calendars.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Globalization.Extensions/tests/System.Globalization.Extensions.Tests.builds b/src/System.Globalization.Extensions/tests/System.Globalization.Extensions.Tests.builds
new file mode 100644
index 000000000000..950e108bd5cc
--- /dev/null
+++ b/src/System.Globalization.Extensions/tests/System.Globalization.Extensions.Tests.builds
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Globalization.Extensions.Tests.csproj">
+      <OSGroup>Unix</OSGroup>
+    </Project>
+    <Project Include="System.Globalization.Extensions.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Globalization/tests/System.Globalization.Tests.builds b/src/System.Globalization/tests/System.Globalization.Tests.builds
new file mode 100644
index 000000000000..a1cec20e8844
--- /dev/null
+++ b/src/System.Globalization/tests/System.Globalization.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Globalization.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.Compression.ZipFile/tests/System.IO.Compression.ZipFile.Tests.builds b/src/System.IO.Compression.ZipFile/tests/System.IO.Compression.ZipFile.Tests.builds
new file mode 100644
index 000000000000..cb16d10cfda1
--- /dev/null
+++ b/src/System.IO.Compression.ZipFile/tests/System.IO.Compression.ZipFile.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.Compression.ZipFile.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.Compression/tests/System.IO.Compression.Tests.builds b/src/System.IO.Compression/tests/System.IO.Compression.Tests.builds
new file mode 100644
index 000000000000..b0d49d346655
--- /dev/null
+++ b/src/System.IO.Compression/tests/System.IO.Compression.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.Compression.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.IO.Compression.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.IO.Compression.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.FileSystem.AccessControl/pkg/System.IO.FileSystem.AccessControl.builds b/src/System.IO.FileSystem.AccessControl/pkg/System.IO.FileSystem.AccessControl.builds
index f05a5d3f4a44..c213a6d77d71 100644
--- a/src/System.IO.FileSystem.AccessControl/pkg/System.IO.FileSystem.AccessControl.builds
+++ b/src/System.IO.FileSystem.AccessControl/pkg/System.IO.FileSystem.AccessControl.builds
@@ -2,7 +2,9 @@
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <ItemGroup>
-    <Project Include="System.IO.FileSystem.AccessControl.pkgproj" />
+    <Project Include="System.IO.FileSystem.AccessControl.pkgproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
 </Project>
diff --git a/src/System.IO.FileSystem.AccessControl/tests/System.IO.FileSystem.AccessControl.Tests.builds b/src/System.IO.FileSystem.AccessControl/tests/System.IO.FileSystem.AccessControl.Tests.builds
new file mode 100644
index 000000000000..2994e868c3c1
--- /dev/null
+++ b/src/System.IO.FileSystem.AccessControl/tests/System.IO.FileSystem.AccessControl.Tests.builds
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.FileSystem.AccessControl.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+    <Project Include="System.IO.FileSystem.AccessControl.Tests.csproj">
+      <OSGroup>Unix</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.builds b/src/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.builds
new file mode 100644
index 000000000000..0fab479f7b1f
--- /dev/null
+++ b/src/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.builds
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.FileSystem.DriveInfo.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="System.IO.FileSystem.DriveInfo.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.IO.FileSystem.DriveInfo.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.IO.FileSystem.DriveInfo.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.csproj b/src/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.csproj
index debc433fcaf0..20b707dd1d9c 100644
--- a/src/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.csproj
+++ b/src/System.IO.FileSystem.DriveInfo/tests/System.IO.FileSystem.DriveInfo.Tests.csproj
@@ -11,7 +11,6 @@
     <RootNamespace>System.IO.FileSystem.DriveInfo.Tests</RootNamespace>
     <AssemblyName>System.IO.FileSystem.DriveInfo.Tests</AssemblyName>
     <ProjectGuid>{7D9E5F2F-5677-40FC-AD04-FA7D603E4806}</ProjectGuid>
-    <UnsupportedPlatforms>OSX</UnsupportedPlatforms>
   </PropertyGroup>
   <!-- Default configurations to help VS understand the configurations -->
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
diff --git a/src/System.IO.FileSystem.Primitives/tests/System.IO.FileSystem.Primitives.Tests.builds b/src/System.IO.FileSystem.Primitives/tests/System.IO.FileSystem.Primitives.Tests.builds
new file mode 100644
index 000000000000..713f4944ba5b
--- /dev/null
+++ b/src/System.IO.FileSystem.Primitives/tests/System.IO.FileSystem.Primitives.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.FileSystem.Primitives.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.FileSystem.Watcher/tests/System.IO.FileSystem.Watcher.Tests.builds b/src/System.IO.FileSystem.Watcher/tests/System.IO.FileSystem.Watcher.Tests.builds
new file mode 100644
index 000000000000..6163a357e735
--- /dev/null
+++ b/src/System.IO.FileSystem.Watcher/tests/System.IO.FileSystem.Watcher.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.FileSystem.Watcher.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.IO.FileSystem.Watcher.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.IO.FileSystem.Watcher.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.builds b/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.builds
new file mode 100644
index 000000000000..e715aadc93f3
--- /dev/null
+++ b/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.builds
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.FileSystem.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="System.IO.FileSystem.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.IO.FileSystem.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.IO.FileSystem.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.MemoryMappedFiles/tests/System.IO.MemoryMappedFiles.Tests.builds b/src/System.IO.MemoryMappedFiles/tests/System.IO.MemoryMappedFiles.Tests.builds
new file mode 100644
index 000000000000..03812305f6e1
--- /dev/null
+++ b/src/System.IO.MemoryMappedFiles/tests/System.IO.MemoryMappedFiles.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.MemoryMappedFiles.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.IO.MemoryMappedFiles.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.IO.MemoryMappedFiles.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.Packaging/tests/System.IO.Packaging.Tests.builds b/src/System.IO.Packaging/tests/System.IO.Packaging.Tests.builds
new file mode 100644
index 000000000000..512c693c51ba
--- /dev/null
+++ b/src/System.IO.Packaging/tests/System.IO.Packaging.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.Packaging.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.Pipes/tests/System.IO.Pipes.Tests.builds b/src/System.IO.Pipes/tests/System.IO.Pipes.Tests.builds
new file mode 100644
index 000000000000..3b4e05f66e42
--- /dev/null
+++ b/src/System.IO.Pipes/tests/System.IO.Pipes.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.Pipes.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.IO.Pipes.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.IO.Pipes.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO.UnmanagedMemoryStream/tests/System.IO.UnmanagedMemoryStream.Tests.builds b/src/System.IO.UnmanagedMemoryStream/tests/System.IO.UnmanagedMemoryStream.Tests.builds
new file mode 100644
index 000000000000..5105beed80ee
--- /dev/null
+++ b/src/System.IO.UnmanagedMemoryStream/tests/System.IO.UnmanagedMemoryStream.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.UnmanagedMemoryStream.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO/src/System.IO.csproj b/src/System.IO/src/System.IO.csproj
index f4d33b0c717d..bc7a4572491e 100644
--- a/src/System.IO/src/System.IO.csproj
+++ b/src/System.IO/src/System.IO.csproj
@@ -31,7 +31,7 @@
     <ProjectReference Include="..\..\System.Diagnostics.Debug\src\System.Diagnostics.Debug.csproj">
       <Project>{E7E8DE8A-9EC1-46A8-A6EE-727DB32DBEB8}</Project>
       <Name>System.Diagnostics.Debug</Name>
-      <OSGroup>Windows_NT</OSGroup>
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
   </ItemGroup>
   <ItemGroup Condition="'$(TargetGroup)' != 'net462'">
diff --git a/src/System.IO/tests/System.IO.Tests.builds b/src/System.IO/tests/System.IO.Tests.builds
new file mode 100644
index 000000000000..f7d875044fe7
--- /dev/null
+++ b/src/System.IO/tests/System.IO.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.IO.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.IO/tests/System.IO.Tests.csproj b/src/System.IO/tests/System.IO.Tests.csproj
index 9b46ef4a5954..be6b0690fc59 100644
--- a/src/System.IO/tests/System.IO.Tests.csproj
+++ b/src/System.IO/tests/System.IO.Tests.csproj
@@ -47,13 +47,14 @@
       <OutputItemType>Content</OutputItemType>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
       <Targets>Build;DebugSymbolsProjectOutputGroup</Targets>
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
     <ProjectReference Include="..\..\System.Diagnostics.Debug\src\System.Diagnostics.Debug.csproj">
       <ReferenceOutputAssembly>false</ReferenceOutputAssembly>
       <OutputItemType>Content</OutputItemType>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
       <Targets>Build;DebugSymbolsProjectOutputGroup</Targets>
-      <OSGroup>$(OSGroup)</OSGroup>
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
diff --git a/src/System.Linq.Expressions/tests/System.Linq.Expressions.Tests.builds b/src/System.Linq.Expressions/tests/System.Linq.Expressions.Tests.builds
new file mode 100644
index 000000000000..446beb127578
--- /dev/null
+++ b/src/System.Linq.Expressions/tests/System.Linq.Expressions.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Linq.Expressions.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Linq.Parallel/tests/System.Linq.Parallel.Tests.builds b/src/System.Linq.Parallel/tests/System.Linq.Parallel.Tests.builds
new file mode 100644
index 000000000000..67f3928252cf
--- /dev/null
+++ b/src/System.Linq.Parallel/tests/System.Linq.Parallel.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Linq.Parallel.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Linq.Queryable/tests/System.Linq.Queryable.Tests.builds b/src/System.Linq.Queryable/tests/System.Linq.Queryable.Tests.builds
new file mode 100644
index 000000000000..494e69f73709
--- /dev/null
+++ b/src/System.Linq.Queryable/tests/System.Linq.Queryable.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Linq.Queryable.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Linq/tests/System.Linq.Tests.builds b/src/System.Linq/tests/System.Linq.Tests.builds
new file mode 100644
index 000000000000..737cfd222112
--- /dev/null
+++ b/src/System.Linq/tests/System.Linq.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Linq.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Net.Http.WinHttpHandler/pkg/System.Net.Http.WinHttpHandler.builds b/src/System.Net.Http.WinHttpHandler/pkg/System.Net.Http.WinHttpHandler.builds
index 6df46c8907a3..8b2e254fe92b 100644
--- a/src/System.Net.Http.WinHttpHandler/pkg/System.Net.Http.WinHttpHandler.builds
+++ b/src/System.Net.Http.WinHttpHandler/pkg/System.Net.Http.WinHttpHandler.builds
@@ -2,7 +2,9 @@
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <ItemGroup>
-    <Project Include="System.Net.Http.WinHttpHandler.pkgproj" />
+    <Project Include="System.Net.Http.WinHttpHandler.pkgproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
 </Project>
diff --git a/src/System.Net.Http/tests/System.Net.Http.Tests.builds b/src/System.Net.Http/tests/System.Net.Http.Tests.builds
new file mode 100644
index 000000000000..7779ac6a800f
--- /dev/null
+++ b/src/System.Net.Http/tests/System.Net.Http.Tests.builds
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="UnitTests\System.Net.Http.Unit.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.Http.Unit.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.Http.Unit.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.Http.Unit.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Http.Functional.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Http.Functional.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Http.Functional.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Http.Functional.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Net.NameResolution/tests/System.Net.NameResolution.Tests.builds b/src/System.Net.NameResolution/tests/System.Net.NameResolution.Tests.builds
new file mode 100644
index 000000000000..112ef61e0d1c
--- /dev/null
+++ b/src/System.Net.NameResolution/tests/System.Net.NameResolution.Tests.builds
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="FunctionalTests\System.Net.NameResolution.Functional.Tests.csproj" >
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.NameResolution.Functional.Tests.csproj" >
+      <OSGroup>Unix</OSGroup>
+    </Project>
+    <Project Include="PalTests\System.Net.NameResolution.Pal.Tests.csproj" >
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+    <Project Include="PalTests\System.Net.NameResolution.Pal.Tests.csproj" >
+      <OSGroup>Unix</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Net.NetworkInformation/tests/System.Net.NetworkInformation.Tests.builds b/src/System.Net.NetworkInformation/tests/System.Net.NetworkInformation.Tests.builds
new file mode 100644
index 000000000000..4bf31df46bf5
--- /dev/null
+++ b/src/System.Net.NetworkInformation/tests/System.Net.NetworkInformation.Tests.builds
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="FunctionalTests\System.Net.NetworkInformation.Functional.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.NetworkInformation.Functional.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.NetworkInformation.Functional.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.NetworkInformation.WinRT.Unit.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.NetworkInformation.WinRT.Unit.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.NetworkInformation.WinRT.Unit.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Net.Ping/tests/System.Net.Ping.Functional.Tests.builds b/src/System.Net.Ping/tests/System.Net.Ping.Functional.Tests.builds
new file mode 100644
index 000000000000..9f82e8dfbb34
--- /dev/null
+++ b/src/System.Net.Ping/tests/System.Net.Ping.Functional.Tests.builds
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="FunctionalTests\System.Net.Ping.Functional.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Ping.Functional.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Ping.Functional.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Ping.Functional.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Net.Primitives/tests/System.Net.Primitives.UnitTests.Tests.builds b/src/System.Net.Primitives/tests/System.Net.Primitives.UnitTests.Tests.builds
new file mode 100644
index 000000000000..003b03492a27
--- /dev/null
+++ b/src/System.Net.Primitives/tests/System.Net.Primitives.UnitTests.Tests.builds
@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="FunctionalTests\System.Net.Primitives.Functional.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Primitives.Functional.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Primitives.Functional.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+    <Project Include="PalTests\System.Net.Primitives.Pal.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="PalTests\System.Net.Primitives.Pal.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="PalTests\System.Net.Primitives.Pal.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.Primitives.UnitTests.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.Primitives.UnitTests.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.Primitives.UnitTests.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Net.Requests/tests/System.Net.Requests.Tests.builds b/src/System.Net.Requests/tests/System.Net.Requests.Tests.builds
new file mode 100644
index 000000000000..6172cf4d519c
--- /dev/null
+++ b/src/System.Net.Requests/tests/System.Net.Requests.Tests.builds
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Net.Requests.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="System.Net.Requests.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Net.Requests.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Net.Requests.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Net.Security/tests/System.Net.Security.Unit.Tests.builds b/src/System.Net.Security/tests/System.Net.Security.Unit.Tests.builds
new file mode 100644
index 000000000000..ae5d22908d49
--- /dev/null
+++ b/src/System.Net.Security/tests/System.Net.Security.Unit.Tests.builds
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="FunctionalTests\System.Net.Security.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Security.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Security.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.Security.Unit.Tests.csproj" >
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.Security.Unit.Tests.csproj" >
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="UnitTests\System.Net.Security.Unit.Tests.csproj" >
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Net.Sockets/src/System.Net.Sockets.csproj b/src/System.Net.Sockets/src/System.Net.Sockets.csproj
index fbfbb3d42eca..2469f2261393 100644
--- a/src/System.Net.Sockets/src/System.Net.Sockets.csproj
+++ b/src/System.Net.Sockets/src/System.Net.Sockets.csproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <Configuration Condition="'$(Configuration)'==''">Windows_Debug</Configuration>
+    <Configuration Condition=" '$(Configuration)' == '' ">$(OS)_Debug</Configuration>
   </PropertyGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <PropertyGroup>
diff --git a/src/System.Net.Sockets/tests/FunctionalTests/System.Net.Sockets.Tests.csproj b/src/System.Net.Sockets/tests/FunctionalTests/System.Net.Sockets.Tests.csproj
index 8b8092eb129d..dc69215f34e8 100644
--- a/src/System.Net.Sockets/tests/FunctionalTests/System.Net.Sockets.Tests.csproj
+++ b/src/System.Net.Sockets/tests/FunctionalTests/System.Net.Sockets.Tests.csproj
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
-  <PropertyGroup>
-    <Configuration Condition="'$(Configuration)'==''">Windows_Debug</Configuration>
-  </PropertyGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
diff --git a/src/System.Net.Sockets/tests/PerformanceTests/System.Net.Sockets.Async.Performance.Tests.csproj b/src/System.Net.Sockets/tests/PerformanceTests/System.Net.Sockets.Async.Performance.Tests.csproj
index b707c068816a..154352d1631f 100644
--- a/src/System.Net.Sockets/tests/PerformanceTests/System.Net.Sockets.Async.Performance.Tests.csproj
+++ b/src/System.Net.Sockets/tests/PerformanceTests/System.Net.Sockets.Async.Performance.Tests.csproj
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
-  <PropertyGroup>
-    <Configuration Condition="'$(Configuration)'==''">Windows_Debug</Configuration>
-  </PropertyGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <PropertyGroup>
     <ProjectGuid>{BB5C85AD-C51A-4903-80E9-6F6E1AC1AD34}</ProjectGuid>
diff --git a/src/System.Net.Sockets/tests/System.Net.Sockets.Tests.builds b/src/System.Net.Sockets/tests/System.Net.Sockets.Tests.builds
new file mode 100644
index 000000000000..6ac94a79aeba
--- /dev/null
+++ b/src/System.Net.Sockets/tests/System.Net.Sockets.Tests.builds
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="FunctionalTests\System.Net.Sockets.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Sockets.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="FunctionalTests\System.Net.Sockets.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="PerformanceTests\System.Net.Sockets.Async.Performance.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="PerformanceTests\System.Net.Sockets.Async.Performance.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="PerformanceTests\System.Net.Sockets.Async.Performance.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Net.WebHeaderCollection/tests/System.Net.WebHeaderCollection.Tests.builds b/src/System.Net.WebHeaderCollection/tests/System.Net.WebHeaderCollection.Tests.builds
new file mode 100644
index 000000000000..06cb3f33dd07
--- /dev/null
+++ b/src/System.Net.WebHeaderCollection/tests/System.Net.WebHeaderCollection.Tests.builds
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Net.WebHeaderCollection.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="System.Net.WebHeaderCollection.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Net.WebHeaderCollection.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Net.WebHeaderCollection.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Net.WebSockets.Client/tests/System.Net.WebSockets.Client.Tests.builds b/src/System.Net.WebSockets.Client/tests/System.Net.WebSockets.Client.Tests.builds
new file mode 100644
index 000000000000..43b977017d09
--- /dev/null
+++ b/src/System.Net.WebSockets.Client/tests/System.Net.WebSockets.Client.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Net.WebSockets.Client.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Net.WebSockets.Client.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Net.WebSockets.Client.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Net.WebSockets/tests/System.Net.WebSockets.Tests.builds b/src/System.Net.WebSockets/tests/System.Net.WebSockets.Tests.builds
new file mode 100644
index 000000000000..c6bb35536d2a
--- /dev/null
+++ b/src/System.Net.WebSockets/tests/System.Net.WebSockets.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Net.WebSockets.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Numerics.Vectors/tests/System.Numerics.Vectors.Tests.builds b/src/System.Numerics.Vectors/tests/System.Numerics.Vectors.Tests.builds
new file mode 100644
index 000000000000..3aae63c50851
--- /dev/null
+++ b/src/System.Numerics.Vectors/tests/System.Numerics.Vectors.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Numerics.Vectors.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.ObjectModel/tests/System.ObjectModel.Tests.builds b/src/System.ObjectModel/tests/System.ObjectModel.Tests.builds
new file mode 100644
index 000000000000..88c16050a7f8
--- /dev/null
+++ b/src/System.ObjectModel/tests/System.ObjectModel.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.ObjectModel.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Private.Uri/tests/System.Private.Uri.Tests.builds b/src/System.Private.Uri/tests/System.Private.Uri.Tests.builds
new file mode 100644
index 000000000000..0b2a5cf2eb48
--- /dev/null
+++ b/src/System.Private.Uri/tests/System.Private.Uri.Tests.builds
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Private.Uri.Tests.csproj">
+      <OSGroup>Unix</OSGroup>
+    </Project>
+    <Project Include="System.Private.Uri.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Private.Uri/tests/System.Private.Uri.Tests.csproj b/src/System.Private.Uri/tests/System.Private.Uri.Tests.csproj
index 1f679570eab7..6cb415e45d71 100644
--- a/src/System.Private.Uri/tests/System.Private.Uri.Tests.csproj
+++ b/src/System.Private.Uri/tests/System.Private.Uri.Tests.csproj
@@ -1,25 +1,15 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
-    <Configuration Condition="'$(Configuration)'==''">Windows_Debug</Configuration>
-  </PropertyGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Windows_Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
     <ProjectGuid>{B0FFC4A8-BAC3-4A7F-8FD5-5B680209371C}</ProjectGuid>
     <OutputType>Library</OutputType>
     <AssemblyName>System.Private.Uri.Tests</AssemblyName>
     <UnsupportedPlatforms>FreeBSD</UnsupportedPlatforms>
   </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'FreeBSD_Debug|AnyCPU'" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'FreeBSD_Release|AnyCPU'" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Linux_Debug|AnyCPU'" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Linux_Release|AnyCPU'" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'OSX_Debug|AnyCPU'" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'OSX_Release|AnyCPU'" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Windows_Debug|AnyCPU'" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Windows_Release|AnyCPU'" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|AnyCPU'" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|AnyCPU'" />
   <ItemGroup>
     <Compile Include="UriBuilderTests.cs" />
   </ItemGroup>
diff --git a/src/System.Reflection.Context/tests/System.Reflection.Context.Tests.builds b/src/System.Reflection.Context/tests/System.Reflection.Context.Tests.builds
new file mode 100644
index 000000000000..d399956939f8
--- /dev/null
+++ b/src/System.Reflection.Context/tests/System.Reflection.Context.Tests.builds
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Reflection.Context.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Reflection.Context/tests/System.Reflection.Context.Tests.csproj b/src/System.Reflection.Context/tests/System.Reflection.Context.Tests.csproj
index c87ad9fca886..9e69f43f7019 100644
--- a/src/System.Reflection.Context/tests/System.Reflection.Context.Tests.csproj
+++ b/src/System.Reflection.Context/tests/System.Reflection.Context.Tests.csproj
@@ -5,6 +5,7 @@
     <ProjectGuid>{D77FBA6C-1AA6-45A4-93E2-97A370672C53}</ProjectGuid>
     <AssemblyName>System.Reflection.Context.Tests</AssemblyName>
     <RootNamespace>System.Reflection.Context.Tests</RootNamespace>
+    <UnsupportedPlatforms>FreeBSD;Linux;NetBSD;OSX</UnsupportedPlatforms>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|AnyCPU'" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|AnyCPU'" />
diff --git a/src/System.Reflection.DispatchProxy/tests/System.Reflection.DispatchProxy.Tests.builds b/src/System.Reflection.DispatchProxy/tests/System.Reflection.DispatchProxy.Tests.builds
new file mode 100644
index 000000000000..1011680d8c1d
--- /dev/null
+++ b/src/System.Reflection.DispatchProxy/tests/System.Reflection.DispatchProxy.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Reflection.DispatchProxy.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Reflection.Emit.ILGeneration/tests/System.Reflection.Emit.ILGeneration.Tests.builds b/src/System.Reflection.Emit.ILGeneration/tests/System.Reflection.Emit.ILGeneration.Tests.builds
new file mode 100644
index 000000000000..985922b21b2c
--- /dev/null
+++ b/src/System.Reflection.Emit.ILGeneration/tests/System.Reflection.Emit.ILGeneration.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Reflection.Emit.ILGeneration.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Reflection.Emit.Lightweight/tests/System.Reflection.Emit.Lightweight.Tests.builds b/src/System.Reflection.Emit.Lightweight/tests/System.Reflection.Emit.Lightweight.Tests.builds
new file mode 100644
index 000000000000..c3971f2842ad
--- /dev/null
+++ b/src/System.Reflection.Emit.Lightweight/tests/System.Reflection.Emit.Lightweight.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Reflection.Emit.Lightweight.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Reflection.Emit/tests/System.Reflection.Emit.Tests.builds b/src/System.Reflection.Emit/tests/System.Reflection.Emit.Tests.builds
new file mode 100644
index 000000000000..d8a6423ca9b1
--- /dev/null
+++ b/src/System.Reflection.Emit/tests/System.Reflection.Emit.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Reflection.Emit.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Reflection.Extensions/tests/System.Reflection.Extensions.Tests.builds b/src/System.Reflection.Extensions/tests/System.Reflection.Extensions.Tests.builds
new file mode 100644
index 000000000000..1cc0a9cb94c8
--- /dev/null
+++ b/src/System.Reflection.Extensions/tests/System.Reflection.Extensions.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Reflection.Extensions.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Reflection.Metadata/tests/System.Reflection.Metadata.Tests.builds b/src/System.Reflection.Metadata/tests/System.Reflection.Metadata.Tests.builds
new file mode 100644
index 000000000000..51a53577a5ba
--- /dev/null
+++ b/src/System.Reflection.Metadata/tests/System.Reflection.Metadata.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Reflection.Metadata.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Reflection.TypeExtensions/tests/System.Reflection.TypeExtensions.Tests.builds b/src/System.Reflection.TypeExtensions/tests/System.Reflection.TypeExtensions.Tests.builds
new file mode 100644
index 000000000000..2d40ce7eb90a
--- /dev/null
+++ b/src/System.Reflection.TypeExtensions/tests/System.Reflection.TypeExtensions.Tests.builds
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Reflection.TypeExtensions.Tests.csproj" />
+    <Project Include="CoreCLR\System.Reflection.TypeExtensions.CoreCLR.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Reflection/tests/System.Reflection.Tests.builds b/src/System.Reflection/tests/System.Reflection.Tests.builds
new file mode 100644
index 000000000000..5f011998c61c
--- /dev/null
+++ b/src/System.Reflection/tests/System.Reflection.Tests.builds
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Reflection.Tests.csproj" />
+    <Project Include="CoreCLR\System.Reflection.CoreCLR.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Resources.Reader/tests/System.Resources.Reader.Tests.builds b/src/System.Resources.Reader/tests/System.Resources.Reader.Tests.builds
new file mode 100644
index 000000000000..01ec8a45124b
--- /dev/null
+++ b/src/System.Resources.Reader/tests/System.Resources.Reader.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Resources.Reader.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Resources.ReaderWriter/tests/System.Resources.ReaderWriter.Tests.builds b/src/System.Resources.ReaderWriter/tests/System.Resources.ReaderWriter.Tests.builds
new file mode 100644
index 000000000000..5059306af188
--- /dev/null
+++ b/src/System.Resources.ReaderWriter/tests/System.Resources.ReaderWriter.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Resources.ReaderWriter.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Resources.ResourceManager/tests/System.Resources.ResourceManager.Tests.builds b/src/System.Resources.ResourceManager/tests/System.Resources.ResourceManager.Tests.builds
new file mode 100644
index 000000000000..54b514fd2204
--- /dev/null
+++ b/src/System.Resources.ResourceManager/tests/System.Resources.ResourceManager.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Resources.ResourceManager.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Resources.Writer/tests/System.Resources.Writer.Tests.builds b/src/System.Resources.Writer/tests/System.Resources.Writer.Tests.builds
new file mode 100644
index 000000000000..a275b08ade33
--- /dev/null
+++ b/src/System.Resources.Writer/tests/System.Resources.Writer.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Resources.Writer.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.builds b/src/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.builds
new file mode 100644
index 000000000000..3a7b28f42182
--- /dev/null
+++ b/src/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.builds
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Runtime.Extensions.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="System.Runtime.Extensions.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Runtime.Extensions.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Runtime.Extensions.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Runtime.Handles/tests/System.Runtime.Handles.Tests.builds b/src/System.Runtime.Handles/tests/System.Runtime.Handles.Tests.builds
new file mode 100644
index 000000000000..69a7aae7eb94
--- /dev/null
+++ b/src/System.Runtime.Handles/tests/System.Runtime.Handles.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Runtime.Handles.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Runtime.InteropServices.PInvoke/tests/System.Runtime.InteropServices.PInvoke.Tests.builds b/src/System.Runtime.InteropServices.PInvoke/tests/System.Runtime.InteropServices.PInvoke.Tests.builds
new file mode 100644
index 000000000000..1e49ee844225
--- /dev/null
+++ b/src/System.Runtime.InteropServices.PInvoke/tests/System.Runtime.InteropServices.PInvoke.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Runtime.InteropServices.PInvoke.Tests.csproj"/>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Runtime.InteropServices.RuntimeInformation/tests/System.Runtime.InteropServices.RuntimeInformation.Tests.builds b/src/System.Runtime.InteropServices.RuntimeInformation/tests/System.Runtime.InteropServices.RuntimeInformation.Tests.builds
new file mode 100644
index 000000000000..830c5f8caa53
--- /dev/null
+++ b/src/System.Runtime.InteropServices.RuntimeInformation/tests/System.Runtime.InteropServices.RuntimeInformation.Tests.builds
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Runtime.InteropServices.RuntimeInformation.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="System.Runtime.InteropServices.RuntimeInformation.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Runtime.InteropServices.RuntimeInformation.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Runtime.InteropServices.RuntimeInformation.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.Tests.builds b/src/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.Tests.builds
new file mode 100644
index 000000000000..6515ee390490
--- /dev/null
+++ b/src/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Runtime.InteropServices.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.Tests.csproj b/src/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.Tests.csproj
index 60d17e606eb7..5f501d9a4694 100644
--- a/src/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.Tests.csproj
+++ b/src/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.Tests.csproj
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
-    <Configuration Condition="'$(Configuration)'==''">Windows_Debug</Configuration>
-  </PropertyGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
diff --git a/src/System.Runtime.Loader/tests/System.Runtime.Loader.Tests.builds b/src/System.Runtime.Loader/tests/System.Runtime.Loader.Tests.builds
new file mode 100644
index 000000000000..a2e63caaaae8
--- /dev/null
+++ b/src/System.Runtime.Loader/tests/System.Runtime.Loader.Tests.builds
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Runtime.Loader.Tests.csproj" />
+    <Project Include="DefaultContext\System.Runtime.Loader.DefaultContext.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Runtime.Numerics/tests/System.Runtime.Numerics.Tests.builds b/src/System.Runtime.Numerics/tests/System.Runtime.Numerics.Tests.builds
new file mode 100644
index 000000000000..95d25fed9735
--- /dev/null
+++ b/src/System.Runtime.Numerics/tests/System.Runtime.Numerics.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Runtime.Numerics.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Runtime.Serialization.Json/tests/System.Runtime.Serialization.Json.Tests.builds b/src/System.Runtime.Serialization.Json/tests/System.Runtime.Serialization.Json.Tests.builds
new file mode 100644
index 000000000000..e597cf38072a
--- /dev/null
+++ b/src/System.Runtime.Serialization.Json/tests/System.Runtime.Serialization.Json.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Runtime.Serialization.Json.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Runtime.Serialization.Xml/tests/System.Runtime.Serialization.Xml.Tests.builds b/src/System.Runtime.Serialization.Xml/tests/System.Runtime.Serialization.Xml.Tests.builds
new file mode 100644
index 000000000000..a304300367a7
--- /dev/null
+++ b/src/System.Runtime.Serialization.Xml/tests/System.Runtime.Serialization.Xml.Tests.builds
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Runtime.Serialization.Xml.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Runtime/tests/System.Runtime.Tests.builds b/src/System.Runtime/tests/System.Runtime.Tests.builds
new file mode 100644
index 000000000000..b07183c6e202
--- /dev/null
+++ b/src/System.Runtime/tests/System.Runtime.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Runtime.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Runtime/tests/System.Runtime.Tests.csproj b/src/System.Runtime/tests/System.Runtime.Tests.csproj
index b498d8abbeea..a0994bfed210 100644
--- a/src/System.Runtime/tests/System.Runtime.Tests.csproj
+++ b/src/System.Runtime/tests/System.Runtime.Tests.csproj
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
-    <Configuration Condition="'$(Configuration)'==''">Windows_Debug</Configuration>
-  </PropertyGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -140,6 +137,7 @@
       <OutputItemType>Content</OutputItemType>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
       <Targets>Build;DebugSymbolsProjectOutputGroup</Targets>
+      <OSGroup>Windows_NT</OSGroup>
     </ProjectReference>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
diff --git a/src/System.Security.AccessControl/pkg/System.Security.AccessControl.builds b/src/System.Security.AccessControl/pkg/System.Security.AccessControl.builds
index 33926d0b961b..9443c7339962 100644
--- a/src/System.Security.AccessControl/pkg/System.Security.AccessControl.builds
+++ b/src/System.Security.AccessControl/pkg/System.Security.AccessControl.builds
@@ -2,7 +2,9 @@
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <ItemGroup>
-    <Project Include="System.Security.AccessControl.pkgproj" />
+    <Project Include="System.Security.AccessControl.pkgproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
 </Project>
diff --git a/src/System.Security.Claims/tests/System.Security.Claims.Tests.builds b/src/System.Security.Claims/tests/System.Security.Claims.Tests.builds
new file mode 100644
index 000000000000..d3dcb5bbc3d5
--- /dev/null
+++ b/src/System.Security.Claims/tests/System.Security.Claims.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Security.Claims.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Security.Cryptography.Algorithms/tests/System.Security.Cryptography.Algorithms.Tests.builds b/src/System.Security.Cryptography.Algorithms/tests/System.Security.Cryptography.Algorithms.Tests.builds
new file mode 100644
index 000000000000..4702748cc180
--- /dev/null
+++ b/src/System.Security.Cryptography.Algorithms/tests/System.Security.Cryptography.Algorithms.Tests.builds
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Security.Cryptography.Algorithms.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="System.Security.Cryptography.Algorithms.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Security.Cryptography.Algorithms.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Security.Cryptography.Algorithms.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Security.Cryptography.Cng/pkg/System.Security.Cryptography.Cng.builds b/src/System.Security.Cryptography.Cng/pkg/System.Security.Cryptography.Cng.builds
index 6fe6460da977..54909b72fdda 100644
--- a/src/System.Security.Cryptography.Cng/pkg/System.Security.Cryptography.Cng.builds
+++ b/src/System.Security.Cryptography.Cng/pkg/System.Security.Cryptography.Cng.builds
@@ -2,7 +2,9 @@
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <ItemGroup>
-    <Project Include="System.Security.Cryptography.Cng.pkgproj" />
+    <Project Include="System.Security.Cryptography.Cng.pkgproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
 </Project>
diff --git a/src/System.Security.Cryptography.Cng/tests/System.Security.Cryptography.Cng.Tests.builds b/src/System.Security.Cryptography.Cng/tests/System.Security.Cryptography.Cng.Tests.builds
new file mode 100644
index 000000000000..01eead731b53
--- /dev/null
+++ b/src/System.Security.Cryptography.Cng/tests/System.Security.Cryptography.Cng.Tests.builds
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Security.Cryptography.Cng.Tests.csproj">
+        <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Security.Cryptography.Csp/pkg/System.Security.Cryptography.Csp.builds b/src/System.Security.Cryptography.Csp/pkg/System.Security.Cryptography.Csp.builds
index 47f387787afc..c6ae8b703ea6 100644
--- a/src/System.Security.Cryptography.Csp/pkg/System.Security.Cryptography.Csp.builds
+++ b/src/System.Security.Cryptography.Csp/pkg/System.Security.Cryptography.Csp.builds
@@ -2,7 +2,9 @@
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <ItemGroup>
-    <Project Include="System.Security.Cryptography.Csp.pkgproj" />
+    <Project Include="System.Security.Cryptography.Csp.pkgproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
 </Project>
diff --git a/src/System.Security.Cryptography.Csp/tests/System.Security.Cryptography.Csp.Tests.builds b/src/System.Security.Cryptography.Csp/tests/System.Security.Cryptography.Csp.Tests.builds
new file mode 100644
index 000000000000..f1463c26ac01
--- /dev/null
+++ b/src/System.Security.Cryptography.Csp/tests/System.Security.Cryptography.Csp.Tests.builds
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Security.Cryptography.Csp.Tests.csproj">
+        <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Security.Cryptography.Encoding/tests/System.Security.Cryptography.Encoding.Tests.builds b/src/System.Security.Cryptography.Encoding/tests/System.Security.Cryptography.Encoding.Tests.builds
new file mode 100644
index 000000000000..51111b0b0990
--- /dev/null
+++ b/src/System.Security.Cryptography.Encoding/tests/System.Security.Cryptography.Encoding.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Security.Cryptography.Encoding.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Security.Cryptography.Encoding.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Security.Cryptography.Encoding.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Security.Cryptography.OpenSsl/pkg/System.Security.Cryptography.OpenSsl.builds b/src/System.Security.Cryptography.OpenSsl/pkg/System.Security.Cryptography.OpenSsl.builds
index bf80098367ac..cb01dc4c9f8a 100644
--- a/src/System.Security.Cryptography.OpenSsl/pkg/System.Security.Cryptography.OpenSsl.builds
+++ b/src/System.Security.Cryptography.OpenSsl/pkg/System.Security.Cryptography.OpenSsl.builds
@@ -3,7 +3,7 @@
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <ItemGroup>
     <Project Include="System.Security.Cryptography.OpenSsl.pkgproj">
-      <OSGroup>Linux</OSGroup>
+      <OSGroup>Unix</OSGroup>
     </Project>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
diff --git a/src/System.Security.Cryptography.OpenSsl/tests/System.Security.Cryptography.OpenSsl.Tests.builds b/src/System.Security.Cryptography.OpenSsl/tests/System.Security.Cryptography.OpenSsl.Tests.builds
new file mode 100644
index 000000000000..921c2beac863
--- /dev/null
+++ b/src/System.Security.Cryptography.OpenSsl/tests/System.Security.Cryptography.OpenSsl.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Security.Cryptography.OpenSsl.Tests.csproj">
+      <OSGroup>FreeBSD</OSGroup>
+    </Project>
+    <Project Include="System.Security.Cryptography.OpenSsl.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Security.Cryptography.OpenSsl.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Security.Cryptography.Primitives/tests/System.Security.Cryptography.Primitives.Tests.builds b/src/System.Security.Cryptography.Primitives/tests/System.Security.Cryptography.Primitives.Tests.builds
new file mode 100644
index 000000000000..c564b8a4ef29
--- /dev/null
+++ b/src/System.Security.Cryptography.Primitives/tests/System.Security.Cryptography.Primitives.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Security.Cryptography.Primitives.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Security.Cryptography.X509Certificates/tests/System.Security.Cryptography.X509Certificates.Tests.builds b/src/System.Security.Cryptography.X509Certificates/tests/System.Security.Cryptography.X509Certificates.Tests.builds
new file mode 100644
index 000000000000..c2ebd7e288d8
--- /dev/null
+++ b/src/System.Security.Cryptography.X509Certificates/tests/System.Security.Cryptography.X509Certificates.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Security.Cryptography.X509Certificates.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Security.Cryptography.X509Certificates.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Security.Cryptography.X509Certificates.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Security.Principal.Windows/tests/System.Security.Principal.Windows.Tests.builds b/src/System.Security.Principal.Windows/tests/System.Security.Principal.Windows.Tests.builds
new file mode 100644
index 000000000000..915ef3cc71ee
--- /dev/null
+++ b/src/System.Security.Principal.Windows/tests/System.Security.Principal.Windows.Tests.builds
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Security.Principal.Windows.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Security.Principal/tests/System.Security.Principal.Tests.builds b/src/System.Security.Principal/tests/System.Security.Principal.Tests.builds
new file mode 100644
index 000000000000..cc082b00120d
--- /dev/null
+++ b/src/System.Security.Principal/tests/System.Security.Principal.Tests.builds
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Security.Principal.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Text.Encoding.CodePages/tests/System.Text.Encoding.CodePages.Tests.builds b/src/System.Text.Encoding.CodePages/tests/System.Text.Encoding.CodePages.Tests.builds
new file mode 100644
index 000000000000..9384cae6f48c
--- /dev/null
+++ b/src/System.Text.Encoding.CodePages/tests/System.Text.Encoding.CodePages.Tests.builds
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Text.Encoding.CodePages.Tests.csproj">
+      <OSGroup>Linux</OSGroup>
+    </Project>
+    <Project Include="System.Text.Encoding.CodePages.Tests.csproj">
+      <OSGroup>OSX</OSGroup>
+    </Project>
+    <Project Include="System.Text.Encoding.CodePages.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Text.Encoding.Extensions/tests/System.Text.Encoding.Extensions.Tests.builds b/src/System.Text.Encoding.Extensions/tests/System.Text.Encoding.Extensions.Tests.builds
new file mode 100644
index 000000000000..bb1726f92ebf
--- /dev/null
+++ b/src/System.Text.Encoding.Extensions/tests/System.Text.Encoding.Extensions.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Text.Encoding.Extensions.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Text.Encoding/tests/System.Text.Encoding.Tests.builds b/src/System.Text.Encoding/tests/System.Text.Encoding.Tests.builds
new file mode 100644
index 000000000000..6950d12c8835
--- /dev/null
+++ b/src/System.Text.Encoding/tests/System.Text.Encoding.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Text.Encoding.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Text.Encodings.Web/tests/System.Text.Encodings.Web.Tests.builds b/src/System.Text.Encodings.Web/tests/System.Text.Encodings.Web.Tests.builds
new file mode 100644
index 000000000000..bdda558f4ac4
--- /dev/null
+++ b/src/System.Text.Encodings.Web/tests/System.Text.Encodings.Web.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Text.Encodings.Web.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Text.RegularExpressions/tests/System.Text.RegularExpressions.Tests.builds b/src/System.Text.RegularExpressions/tests/System.Text.RegularExpressions.Tests.builds
new file mode 100644
index 000000000000..d31cdc2c0241
--- /dev/null
+++ b/src/System.Text.RegularExpressions/tests/System.Text.RegularExpressions.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Text.RegularExpressions.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Threading.AccessControl/tests/System.Threading.AccessControl.Tests.builds b/src/System.Threading.AccessControl/tests/System.Threading.AccessControl.Tests.builds
new file mode 100644
index 000000000000..62218e82bf08
--- /dev/null
+++ b/src/System.Threading.AccessControl/tests/System.Threading.AccessControl.Tests.builds
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Threading.AccessControl.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Threading.AccessControl/tests/System.Threading.AccessControl.Tests.csproj b/src/System.Threading.AccessControl/tests/System.Threading.AccessControl.Tests.csproj
index 328f8c3eea28..2e1d30c732c0 100644
--- a/src/System.Threading.AccessControl/tests/System.Threading.AccessControl.Tests.csproj
+++ b/src/System.Threading.AccessControl/tests/System.Threading.AccessControl.Tests.csproj
@@ -16,6 +16,7 @@
     <ProjectReference Include="..\src\System.Threading.AccessControl.csproj">
       <Project>{E3ED83FD-3015-4BD8-A1B8-6294986E6CFA}</Project>
       <Name>System.Threading.AccessControl</Name>
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
diff --git a/src/System.Threading.Overlapped/tests/System.Threading.Overlapped.Tests.builds b/src/System.Threading.Overlapped/tests/System.Threading.Overlapped.Tests.builds
new file mode 100644
index 000000000000..f7f976fecf40
--- /dev/null
+++ b/src/System.Threading.Overlapped/tests/System.Threading.Overlapped.Tests.builds
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Threading.Overlapped.Tests.csproj">
+      <OSGroup>Windows_NT</OSGroup>
+    </Project>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Threading.Tasks.Dataflow/tests/System.Threading.Tasks.Dataflow.Tests.builds b/src/System.Threading.Tasks.Dataflow/tests/System.Threading.Tasks.Dataflow.Tests.builds
new file mode 100644
index 000000000000..288a8662b08c
--- /dev/null
+++ b/src/System.Threading.Tasks.Dataflow/tests/System.Threading.Tasks.Dataflow.Tests.builds
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Threading.Tasks.Dataflow.Tests.csproj" />
+    <Project Include="System.Threading.Tasks.Dataflow.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Threading.Tasks.Extensions/tests/System.Threading.Tasks.Extensions.Tests.builds b/src/System.Threading.Tasks.Extensions/tests/System.Threading.Tasks.Extensions.Tests.builds
new file mode 100644
index 000000000000..2a83532d8dba
--- /dev/null
+++ b/src/System.Threading.Tasks.Extensions/tests/System.Threading.Tasks.Extensions.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Threading.Tasks.Extensions.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Threading.Tasks.Parallel/tests/System.Threading.Tasks.Parallel.Tests.builds b/src/System.Threading.Tasks.Parallel/tests/System.Threading.Tasks.Parallel.Tests.builds
new file mode 100644
index 000000000000..11582fbd6bcc
--- /dev/null
+++ b/src/System.Threading.Tasks.Parallel/tests/System.Threading.Tasks.Parallel.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Threading.Tasks.Parallel.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Threading.Tasks/src/System.Threading.Tasks.csproj b/src/System.Threading.Tasks/src/System.Threading.Tasks.csproj
index 868ba88326db..2a226f34f4bb 100644
--- a/src/System.Threading.Tasks/src/System.Threading.Tasks.csproj
+++ b/src/System.Threading.Tasks/src/System.Threading.Tasks.csproj
@@ -19,8 +19,8 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'netcore50aot_Release|AnyCPU'" />
   <ItemGroup Condition="'$(TargetGroup)' == ''">
     <Compile Include="System\Threading\Tasks\TaskExtensions.CoreCLR.cs" />
-    <ProjectReference Include="..\..\System.Diagnostics.Debug\src\System.Diagnostics.Debug.csproj">
-      <OSGroup>Windows_NT</OSGroup>
+    <ProjectReference Include="..\..\System.Diagnostics.Debug\src\System.Diagnostics.Debug.csproj" >
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
   </ItemGroup>
   <ItemGroup Condition="'$(TargetGroup)' == 'net46'">
diff --git a/src/System.Threading.Tasks/tests/System.Threading.Tasks.Tests.builds b/src/System.Threading.Tasks/tests/System.Threading.Tasks.Tests.builds
new file mode 100644
index 000000000000..91ec8ee90c1a
--- /dev/null
+++ b/src/System.Threading.Tasks/tests/System.Threading.Tasks.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Threading.Tasks.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Threading.Tasks/tests/System.Threading.Tasks.Tests.csproj b/src/System.Threading.Tasks/tests/System.Threading.Tasks.Tests.csproj
index 7b1f4219fdee..025f4a189ed4 100644
--- a/src/System.Threading.Tasks/tests/System.Threading.Tasks.Tests.csproj
+++ b/src/System.Threading.Tasks/tests/System.Threading.Tasks.Tests.csproj
@@ -17,12 +17,6 @@
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
       <Targets>Build;DebugSymbolsProjectOutputGroup</Targets>
     </ProjectReference>
-    <ProjectReference Include="..\..\System.Diagnostics.Debug\src\System.Diagnostics.Debug.csproj">
-      <ReferenceOutputAssembly>false</ReferenceOutputAssembly>
-      <OutputItemType>Content</OutputItemType>
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-      <Targets>Build;DebugSymbolsProjectOutputGroup</Targets>
-    </ProjectReference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="XunitAssemblyAttributes.cs" />
diff --git a/src/System.Threading.Timer/tests/System.Threading.Timer.Tests.builds b/src/System.Threading.Timer/tests/System.Threading.Timer.Tests.builds
new file mode 100644
index 000000000000..0152f12f42fc
--- /dev/null
+++ b/src/System.Threading.Timer/tests/System.Threading.Timer.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Threading.Timer.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Threading/src/System.Threading.csproj b/src/System.Threading/src/System.Threading.csproj
index 40b8019c5631..c40df0680dc3 100644
--- a/src/System.Threading/src/System.Threading.csproj
+++ b/src/System.Threading/src/System.Threading.csproj
@@ -29,7 +29,7 @@
   </ItemGroup>
   <ItemGroup Condition="'$(TargetGroup)' == ''">
     <ProjectReference Include="..\..\System.Diagnostics.Debug\src\System.Diagnostics.Debug.csproj">
-      <OSGroup>Windows_NT</OSGroup>
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
   </ItemGroup>
   <ItemGroup Condition="'$(TargetGroup)' == 'net46'">
diff --git a/src/System.Threading/tests/System.Threading.Tests.builds b/src/System.Threading/tests/System.Threading.Tests.builds
new file mode 100644
index 000000000000..b0148c21fe97
--- /dev/null
+++ b/src/System.Threading/tests/System.Threading.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Threading.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Threading/tests/System.Threading.Tests.csproj b/src/System.Threading/tests/System.Threading.Tests.csproj
index 2682278cdcb8..b689f24fbab0 100644
--- a/src/System.Threading/tests/System.Threading.Tests.csproj
+++ b/src/System.Threading/tests/System.Threading.Tests.csproj
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
-    <Configuration Condition="'$(Configuration)'==''">Windows_Debug</Configuration>
-  </PropertyGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -65,12 +62,7 @@
       <OutputItemType>Content</OutputItemType>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
       <Targets>Build;DebugSymbolsProjectOutputGroup</Targets>
-    </ProjectReference>
-    <ProjectReference Include="..\..\System.Diagnostics.Debug\src\System.Diagnostics.Debug.csproj">
-      <ReferenceOutputAssembly>false</ReferenceOutputAssembly>
-      <OutputItemType>Content</OutputItemType>
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-      <Targets>Build;DebugSymbolsProjectOutputGroup</Targets>
+      <OSGroup>$(InputOSGroup)</OSGroup>
     </ProjectReference>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
diff --git a/src/System.Xml.ReaderWriter/tests/System.Xml.ReaderWriter.Tests.builds b/src/System.Xml.ReaderWriter/tests/System.Xml.ReaderWriter.Tests.builds
new file mode 100644
index 000000000000..b73b3ae09c1b
--- /dev/null
+++ b/src/System.Xml.ReaderWriter/tests/System.Xml.ReaderWriter.Tests.builds
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="Readers\CharCheckingReader\System.Xml.RW.CharCheckingReader.Tests.csproj" />
+    <Project Include="Readers\CustomReader\System.Xml.RW.CustomReader.Tests.csproj" />
+    <Project Include="Readers\FactoryReader\System.Xml.RW.FactoryReader.Tests.csproj" />
+    <Project Include="Readers\NameTable\System.Xml.RW.NameTable.Tests.csproj" />
+    <Project Include="Readers\ReaderSettings\System.Xml.RW.ReaderSettings.Tests.csproj" />
+    <Project Include="Readers\SubtreeReader\System.Xml.RW.SubtreeReader.Tests.csproj" />
+    <Project Include="Readers\WrappedReader\System.Xml.RW.WrappedReader.Tests.csproj" />
+    <Project Include="Writers\RwFactory\System.Xml.RW.RwFactory.Tests.csproj" />
+    <Project Include="Writers\XmlWriterApi\System.Xml.RW.XmlWriterApi.Tests.csproj" />
+    <Project Include="XmlConvert\System.Xml.RW.XmlConvert.Tests.csproj" />
+    <Project Include="XmlReader\ReadContentAs\System.Xml.RW.XmlReader.ReadContentAs.Tests.csproj" />
+    <Project Include="XmlReader\Tests\System.Xml.RW.XmlReader.Tests.csproj" />
+    <Project Include="XmlReader\XmlResolver\System.Xml.RW.XmlSystemPathResolver.Tests.csproj" />
+    <Project Include="XmlReaderLib\System.Xml.RW.XmlReaderLib.csproj" />
+    <Project Include="XmlWriter\System.Xml.RW.XmlWriter.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Xml.XDocument/tests/System.Xml.XDocument.Tests.builds b/src/System.Xml.XDocument/tests/System.Xml.XDocument.Tests.builds
new file mode 100644
index 000000000000..598255750745
--- /dev/null
+++ b/src/System.Xml.XDocument/tests/System.Xml.XDocument.Tests.builds
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="axes\System.Xml.XDocument.Axes.Tests.csproj" />
+    <Project Include="events\System.Xml.XDocument.Events.Tests.csproj" />
+    <Project Include="misc\System.Xml.XDocument.Misc.Tests.csproj" />
+    <Project Include="Properties\System.Xml.XDocument.Properties.Tests.csproj" />
+    <Project Include="SDMSample\System.Xml.XDocument.SDMSample.Tests.csproj" />
+    <Project Include="Streaming\System.Xml.XDocument.Streaming.Tests.csproj" />
+    <Project Include="TreeManipulation\System.Xml.XDocument.TreeManipulation.Tests.csproj" />
+    <Project Include="XDocument.Common\XDocument.Common.csproj" />
+    <Project Include="XDocument.Test.ModuleCore\XDocument.Test.ModuleCore.csproj" />
+    <Project Include="xNodeBuilder\System.Xml.XDocument.xNodeBuilder.Tests.csproj" />
+    <Project Include="xNodeReader\System.Xml.XDocument.xNodeReader.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
diff --git a/src/System.Xml.XPath.XDocument/tests/System.Xml.XPath.XDocument.Tests.builds b/src/System.Xml.XPath.XDocument/tests/System.Xml.XPath.XDocument.Tests.builds
new file mode 100644
index 000000000000..3d8bb465814f
--- /dev/null
+++ b/src/System.Xml.XPath.XDocument/tests/System.Xml.XPath.XDocument.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Xml.XPath.XDocument.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Xml.XPath.XmlDocument/tests/System.Xml.XPath.XmlDocument.Tests.builds b/src/System.Xml.XPath.XmlDocument/tests/System.Xml.XPath.XmlDocument.Tests.builds
new file mode 100644
index 000000000000..8607240e006a
--- /dev/null
+++ b/src/System.Xml.XPath.XmlDocument/tests/System.Xml.XPath.XmlDocument.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Xml.XPath.XmlDocument.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Xml.XPath/tests/System.Xml.XPath.Tests.builds b/src/System.Xml.XPath/tests/System.Xml.XPath.Tests.builds
new file mode 100644
index 000000000000..1c463fc75077
--- /dev/null
+++ b/src/System.Xml.XPath/tests/System.Xml.XPath.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Xml.XPath.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Xml.XmlDocument/tests/System.Xml.XmlDocument.Tests.builds b/src/System.Xml.XmlDocument/tests/System.Xml.XmlDocument.Tests.builds
new file mode 100644
index 000000000000..4397e9957994
--- /dev/null
+++ b/src/System.Xml.XmlDocument/tests/System.Xml.XmlDocument.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Xml.XmlDocument.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/System.Xml.XmlSerializer/tests/System.Xml.XmlSerializer.Tests.builds b/src/System.Xml.XmlSerializer/tests/System.Xml.XmlSerializer.Tests.builds
new file mode 100644
index 000000000000..fc1d12ebc13c
--- /dev/null
+++ b/src/System.Xml.XmlSerializer/tests/System.Xml.XmlSerializer.Tests.builds
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Xml.XmlSerializer.Tests.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>
+
diff --git a/src/tests.builds b/src/tests.builds
index c1fd23c24f82..15bb5bd76bc1 100644
--- a/src/tests.builds
+++ b/src/tests.builds
@@ -6,20 +6,14 @@
   </PropertyGroup>
   
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
-  
   <PropertyGroup>
     <FilterToOSGroup Condition="'$(_OriginalOSGroup)' == ''">$(OSEnvironment)</FilterToOSGroup>
   </PropertyGroup>
-  
+  <PropertyGroup>
+    <BuildAllOSGroups Condition="'$(OSGroup)' != '' OR '$(FilterToOSGroup)' != ''">false</BuildAllOSGroups>
+  </PropertyGroup>
   <ItemGroup>
-    <ExcludeProjects Condition="'$(OSEnvironment)'!='Windows_NT'" Include="**\Microsoft.VisualBasic.Tests.csproj" />
-    <ExcludeProjects Condition="'$(OSGroup)'=='Windows_NT'" Include="**\System.Security.Cryptography.OpenSsl.Tests.csproj" />
-    <Project Include="*\test*\**\*.csproj" Exclude="@(ExcludeProjects)">
-      <OSGroup Condition="'$(FilterToOSGroup)'!=''">$(FilterToOSGroup)</OSGroup>
-    </Project>
-    <Project Include="*\test*\**\*.vbproj" Condition="'$(IncludeVbProjects)'!='false'">
-      <OSGroup Condition="'$(FilterToOSGroup)'!=''">$(FilterToOSGroup)</OSGroup>
-    </Project>
+    <Project Include="*\tests\*.builds" />
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
 </Project>
\ No newline at end of file