diff --git a/build/Microsoft.DotNet.Cli.tasks b/build/Microsoft.DotNet.Cli.tasks
index 49553a226..89c188c72 100644
--- a/build/Microsoft.DotNet.Cli.tasks
+++ b/build/Microsoft.DotNet.Cli.tasks
@@ -9,6 +9,7 @@
   <UsingTask TaskName="Crossgen" AssemblyFile="$(CLIBuildDll)" />
   <UsingTask TaskName="DotNetBuild" AssemblyFile="$(CLIBuildDll)" />
   <UsingTask TaskName="DotNetBuildPJ" AssemblyFile="$(CLIBuildDll)" />
+  <UsingTask TaskName="DotNetMSBuild" AssemblyFile="$(CLIBuildDll)" />
   <UsingTask TaskName="DotNetNew" AssemblyFile="$(CLIBuildDll)" />
   <UsingTask TaskName="DotNetPack" AssemblyFile="$(CLIBuildDll)" />
   <UsingTask TaskName="DotNetPublish" AssemblyFile="$(CLIBuildDll)" />
diff --git a/build_projects/Microsoft.DotNet.Cli.Build.SelfTest/InvokeWithStage0.proj b/build_projects/Microsoft.DotNet.Cli.Build.SelfTest/InvokeWithStage0.proj
new file mode 100644
index 000000000..3437872d9
--- /dev/null
+++ b/build_projects/Microsoft.DotNet.Cli.Build.SelfTest/InvokeWithStage0.proj
@@ -0,0 +1,11 @@
+<Project DefaultTargets="RunValidation">
+    <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+    <Import Project="$(RepoRoot)/build/Microsoft.DotNet.Cli.tasks" />
+    
+    <Target Name="RunValidation">
+        <Message Text="================================"/>
+        <DotNetMSBuild Arguments='$(MSBuildThisFileDirectory)/InvokeWithStage2.proj /p:ToolPath="$(Stage2Dir)"  /v:diag'
+                       ToolPath="$(Stage2Dir)" />
+        <Message Text="================================"/>
+    </Target>
+</Project>
\ No newline at end of file
diff --git a/build_projects/Microsoft.DotNet.Cli.Build.SelfTest/InvokeWithStage2.proj b/build_projects/Microsoft.DotNet.Cli.Build.SelfTest/InvokeWithStage2.proj
new file mode 100644
index 000000000..c27f097ea
--- /dev/null
+++ b/build_projects/Microsoft.DotNet.Cli.Build.SelfTest/InvokeWithStage2.proj
@@ -0,0 +1,25 @@
+<Project DefaultTargets="RunValidation">
+        
+    <PropertyGroup>
+        <MSBuildExtensionsPathInToolPath>false</MSBuildExtensionsPathInToolPath>
+        <MSBuildExtensionsPathInToolPath Condition="$(MSBuildExtensionsPath.StartsWith('$(ToolPath)'))">true</MSBuildExtensionsPathInToolPath>
+        <CscToolExeInToolPath>false</CscToolExeInToolPath>
+        <CscToolExeInToolPath Condition="$(CscToolExe.StartsWith('$(ToolPath)'))">true</CscToolExeInToolPath>
+        <MSBuildSDKsPathInToolPath>false</MSBuildSDKsPathInToolPath>
+        <MSBuildSDKsPathInToolPath Condition="$(MSBuildSDKsPath.StartsWith('$(ToolPath)'))">true</MSBuildSDKsPathInToolPath>
+    </PropertyGroup>
+    
+    <Target Name="RunValidation">
+        <Error Condition=" '$(ToolPath)' == '' "
+            Text="ToolPath not set" />
+
+        <Error Condition=" '$(MSBuildExtensionsPathInToolPath)' == 'false' "
+               Text="MSBuildExtensionsPath '$(MSBuildExtensionsPath)' not in ToolPath '$(ToolPath)'" />
+
+        <Error Condition=" '$(CscToolExeInToolPath)' == 'false' "
+               Text="CscToolExe '$(CscToolExe)' not in ToolPath '$(ToolPath)'" />
+
+        <Error Condition=" '$(MSBuildSDKsPathInToolPath)' == 'false' "
+               Text="MSBuildSDKsPath '$(MSBuildSDKsPath)' not in ToolPath '$(ToolPath)'" />
+    </Target>
+</Project>
\ No newline at end of file
diff --git a/build_projects/dotnet-cli-build/DotNetMSBuild.cs b/build_projects/dotnet-cli-build/DotNetMSBuild.cs
new file mode 100644
index 000000000..c5531b802
--- /dev/null
+++ b/build_projects/dotnet-cli-build/DotNetMSBuild.cs
@@ -0,0 +1,30 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace Microsoft.DotNet.Cli.Build
+{
+    public class DotNetMSBuild : DotNetTool
+    {
+        protected override string Command
+        {
+            get { return "msbuild"; }
+        }
+
+        protected override string Args
+        {
+            get { return $"{GetArguments()}"; }
+        }
+
+        public string Arguments { get; set; }
+
+        private string GetArguments()
+        {
+            if (!string.IsNullOrEmpty(Arguments))
+            {
+                return $"{Arguments}";
+            }
+
+            return null;
+        }
+    }
+}
diff --git a/build_projects/dotnet-cli-build/DotNetTool.cs b/build_projects/dotnet-cli-build/DotNetTool.cs
index 58f813cab..7a12d0355 100644
--- a/build_projects/dotnet-cli-build/DotNetTool.cs
+++ b/build_projects/dotnet-cli-build/DotNetTool.cs
@@ -1,5 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
+using System;
 using System.Linq;
 
 using Microsoft.Build.Framework;
@@ -13,10 +14,20 @@ namespace Microsoft.DotNet.Cli.Build
     {
         public DotNetTool()
         {
+Log.LogMessage(MessageImportance.High, "STARTING "); 
             EnvironmentVariables = new EnvironmentFilter()
                 .GetEnvironmentVariableNamesToRemove()
                 .Select(e => $"{e}=")
                 .ToArray();
+            
+Log.LogMessage(MessageImportance.High, "OVERRIDING "); 
+
+            foreach (var ev in EnvironmentVariables)
+            {
+                Log.LogMessage(MessageImportance.High, $"{ev}");
+            }
+
+            throw new Exception($"{EnvironmentVariables.Count()}");
         }
 
         protected abstract string Command { get; }