diff --git a/nuget/Microsoft.Windows.CsWinRT.targets b/nuget/Microsoft.Windows.CsWinRT.targets
index 2ce814b4d..e9a29d767 100644
--- a/nuget/Microsoft.Windows.CsWinRT.targets
+++ b/nuget/Microsoft.Windows.CsWinRT.targets
@@ -149,8 +149,34 @@ $(CsWinRTFilters)
 
   <!-- Call The GuidPatch tool on the projection .dll -->
   <Target Name="CsWinRTInvokeGuidPatcher" AfterTargets="Compile" BeforeTargets="Link">
-    <Message Text="Preparing to invoke GuidPatcher" />
-     
+
+    <!-- You can use a Directory.Build.props file to set two properties as the path to the patcher and the winrt.runtime used
+          - CsWinRTGuidPatchPath
+          - CsWinRTGuidPatchRuntimeDll
+    -->
+    <PropertyGroup>
+      <CsWinRTGuidPatchExePath Condition="'$(CsWinRTGuidPatchPath)' != ''">$(CsWinRTGuidPatchPath)</CsWinRTGuidPatchExePath>
+      <CsWinRTGuidPatchRuntimeDll Condition="'$(CsWinRTGuidPatchRuntimePath)' != ''">$(CsWinRTGuidPatchRuntimePath)</CsWinRTGuidPatchRuntimeDll> 
+
+      <CsWinRTGuidPatchExePath Condition="'$(CsWinRTGuidPatchPath)' == ''">$(CsWinRTPath)build\tools\</CsWinRTGuidPatchExePath>
+      <CsWinRTGuidPatchRuntimeDll Condition="'$(CsWinRTGuidPatchRuntimePath)' == ''">$(CsWinRTPath)lib\net5.0\</CsWinRTGuidPatchRuntimeDll> 
+
+      <CsWinRTGuidPatchInput Condition="'$(CsWinRTGuidPatchInput)' == ''">@(BuiltProjectOutputGroupKeyOutput->'%(Identity)')</CsWinRTGuidPatchInput>
+    </PropertyGroup>
+    
+
+    <Exec Command="$(CsWinRTGuidPatchExePath)GuidPatch.exe $(CsWinRTGuidPatchInput) $(CsWinRTGuidPatchRuntimeDll)" ConsoleToMsBuild="true">
+      <Output TaskParameter="ConsoleOutput" PropertyName="CsWinRTGuidPatchOutput" />
+    </Exec>
+    <!-- Special case when the GuidPatcherOutput doesn't exist? -->
+    
+    <ItemGroup>
+      <PatchedFiles Include="$(_DirectoryBuildTargetsBasePath)\GuidPatcherOutput\*.dll" />
+    </ItemGroup>
+    
+    <!-- what is the file handed to Link ? Can we pass the output one along? -->
+    <Copy SourceFiles="@(PatchedFiles)" DestinationFolder="$(TargetDir)" />
+
   </Target>
   
   <Import Project="$(MSBuildThisFileDirectory)Microsoft.Windows.CsWinRT.Prerelease.targets" Condition="Exists('$(MSBuildThisFileDirectory)Microsoft.Windows.CsWinRT.Prerelease.targets')"/>
diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index eee4c5c30..a0ee6a9e3 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -26,6 +26,11 @@
     <DefineConstants>$(DefineConstants);MANUAL_IUNKNOWN</DefineConstants>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <CsWinRTGuidPatchPath>$(MSBuildProjectDirectory)\Perf\GuidPatch\bin\$(Platform)\$(Configuration)\net5.0\</CsWinRTGuidPatchPath>
+    <CsWinRTGuidPatchRuntimePath>$(MSBuildProjectDirectory)\WinRT.Runtime\bin\$(Configuration)\net5.0\</CsWinRTGuidPatchRuntimePath>
+  </PropertyGroup>
+
   <PropertyGroup>
     <VersionNumber Condition="'$(VersionNumber)'==''">0.0.0.0</VersionNumber>
     <VersionString Condition="'$(VersionString)'==''">0.0.0-private.0</VersionString>
diff --git a/src/Perf/GuidPatch/GuidPatch.csproj b/src/Perf/GuidPatch/GuidPatch.csproj
index c9ca52748..3d9a8f99a 100644
--- a/src/Perf/GuidPatch/GuidPatch.csproj
+++ b/src/Perf/GuidPatch/GuidPatch.csproj
@@ -4,7 +4,7 @@
     <OutputType>Exe</OutputType>
     <TargetFramework>net5.0</TargetFramework>
     <Nullable>enable</Nullable>
-    <Platforms>AnyCPU;x64;x86</Platforms>
+    <Platforms>AnyCPU</Platforms>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/Perf/GuidPatch/GuidPatcher.cs b/src/Perf/GuidPatch/GuidPatcher.cs
index 2af033fb1..00e7e82cb 100644
--- a/src/Perf/GuidPatch/GuidPatcher.cs
+++ b/src/Perf/GuidPatch/GuidPatcher.cs
@@ -30,7 +30,7 @@ class GuidPatcher
         private readonly TypeDefinition guidDataBlockType;
         private SignatureGenerator signatureGenerator;
 
-        public GuidPatcher(string assemblyPath, IAssemblyResolver assemblyResolver)
+        public GuidPatcher(string assemblyPath, IAssemblyResolver assemblyResolver, AssemblyDefinition winRTRuntime)
         {
             assembly = AssemblyDefinition.ReadAssembly(assemblyPath, new ReaderParameters(ReadingMode.Deferred)
             {
@@ -42,7 +42,7 @@ public GuidPatcher(string assemblyPath, IAssemblyResolver assemblyResolver)
                 ApplyWindowsRuntimeProjections = false
             });
 
-            winRTRuntimeAssembly = assemblyResolver.Resolve(new AssemblyNameReference("WinRT.Runtime", default));
+            winRTRuntimeAssembly = winRTRuntime; // assemblyResolver.Resolve(new AssemblyNameReference("WinRT.Runtime", default));
 
             guidImplementationDetailsType = new TypeDefinition(null, "<GuidPatcherImplementationDetails>", TypeAttributes.AutoClass | TypeAttributes.Sealed, assembly.MainModule.TypeSystem.Object);
 
diff --git a/src/Perf/GuidPatch/Program.cs b/src/Perf/GuidPatch/Program.cs
index 0f993eb01..579788732 100644
--- a/src/Perf/GuidPatch/Program.cs
+++ b/src/Perf/GuidPatch/Program.cs
@@ -1,4 +1,6 @@
-using System;
+using Mono.Cecil;
+using System;
+using System.IO;
 
 namespace GuidPatch
 {
@@ -6,21 +8,35 @@ class Program
     {
         static void Main(string[] args)
         {
-            Console.WriteLine("Hello World!");
+            if (args.Length != 2)
+            {
+                Console.WriteLine($"Expected to be given two arguments. Given {args.Length}");
+            }
+            else
+            {
+                /* The first argument given is the .dll to patch 
+                   The second argument is the folder to look for winrt.runtime in */
+                var resolver = new DefaultAssemblyResolver();
 
-            /*
-            var resolver = new DefaultAssemblyResolver();
-            resolver.AddSearchDirectory("TestData");
-            resolver.AddSearchDirectory("C:/Program Files/dotnet/packs/Microsoft.NETCore.App.Ref/5.0.0/ref/net5.0");
-            var guidPatcher = new GuidPatcher(
-                "TestData/Windows.dll",
-                resolver);
-            int numPatches = guidPatcher.ProcessAssembly();
-            Directory.CreateDirectory("Output");
-            guidPatcher.SaveAssembly("Output");
-
-            Console.WriteLine($"{numPatches} IID calculations/fetches patched");
-            */
+                try
+                {
+                    resolver.AddSearchDirectory(args[1]);
+                    AssemblyDefinition winRTRuntimeAssembly = resolver.Resolve(new AssemblyNameReference("WinRT.Runtime", default));
+                    var guidPatcher = new GuidPatcher(
+                        args[0],
+                        resolver,
+                        winRTRuntimeAssembly);
+                    int numPatches = guidPatcher.ProcessAssembly();
+                    Directory.CreateDirectory("GuidPatcherOutput");
+                    guidPatcher.SaveAssembly("GuidPatcherOutput");
+                    Console.WriteLine($"{numPatches} IID calculations/fetches patched");
+                }
+                catch (AssemblyResolutionException)
+                {
+                    Console.WriteLine("Failed to resolve WinRT.Runtime, shutting down.");
+                    return;
+                }
+            }
         }
     }
 }
diff --git a/src/build.cmd b/src/build.cmd
index d738a1a6b..2ca794b53 100644
--- a/src/build.cmd
+++ b/src/build.cmd
@@ -131,6 +131,7 @@ if ErrorLevel 1 (
   exit /b !ErrorLevel!
 )
 if "%cswinrt_build_only%"=="true" goto :eof
+if "%cswinrt_buildpack%"=="true" goto :package
 
 :test
 :unittest
@@ -184,7 +185,7 @@ set net5_runtime=%this_dir%WinRT.Runtime\bin\%cswinrt_configuration%\net5.0\WinR
 set source_generator=%this_dir%Authoring\WinRT.SourceGenerator\bin\%cswinrt_configuration%\netstandard2.0\WinRT.SourceGenerator.dll
 set winrt_host_%cswinrt_platform%=%this_dir%_build\%cswinrt_platform%\%cswinrt_configuration%\WinRT.Host\bin\WinRT.Host.dll
 set winrt_shim=%this_dir%Authoring\WinRT.Host.Shim\bin\%cswinrt_configuration%\net5.0\WinRT.Host.Shim.dll
-set guid_patch=%this_dir%Perf\GuidPatch\bin\%cswinrt_configuration%\net5.0\GuidPatch.exe
+set guid_patch=%this_dir%Perf\GuidPatch\bin\%cswinrt_platform%\%cswinrt_configuration%\net5.0\GuidPatch.exe
 echo Creating nuget package
 call :exec %nuget_dir%\nuget pack %this_dir%..\nuget\Microsoft.Windows.CsWinRT.nuspec -Properties cswinrt_exe=%cswinrt_exe%;netstandard2_runtime=%netstandard2_runtime%;net5_runtime=%net5_runtime%;source_generator=%source_generator%;cswinrt_nuget_version=%cswinrt_version_string%;winrt_host_x86=%winrt_host_x86%;winrt_host_x64=%winrt_host_x64%;winrt_host_arm=%winrt_host_arm%;winrt_host_arm64=%winrt_host_arm64%;winrt_shim=%winrt_shim%;guid_patch=%guid_patch% -OutputDirectory %cswinrt_bin_dir% -NonInteractive -Verbosity Detailed -NoPackageAnalysis
 goto :eof
diff --git a/src/cswinrt.sln b/src/cswinrt.sln
index b28214168..0f0219794 100644
--- a/src/cswinrt.sln
+++ b/src/cswinrt.sln
@@ -101,7 +101,7 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "AuthoringWinUITest", "Tests
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Perf", "Perf", "{539DBDEF-3B49-4503-9BD3-7EB83C2179CB}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "GuidPatch", "Perf\GuidPatch\GuidPatch.csproj", "{AE3B0611-2FBB-42AB-A245-B4E79868A5F9}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "GuidPatch", "Perf\GuidPatch\GuidPatch.csproj", "{AE3B0611-2FBB-42AB-A245-B4E79868A5F9}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -299,7 +299,6 @@ Global
 		{41E2A272-150F-42F5-AD40-047AAD9088A0}.Release|x86.Build.0 = Release|x86
 		{0212A7C5-8D3F-443C-9EBC-1F28091FDF88}.Debug|Any CPU.ActiveCfg = Debug|Win32
 		{0212A7C5-8D3F-443C-9EBC-1F28091FDF88}.Debug|x64.ActiveCfg = Debug|x64
-		{0212A7C5-8D3F-443C-9EBC-1F28091FDF88}.Debug|x64.Build.0 = Debug|x64
 		{0212A7C5-8D3F-443C-9EBC-1F28091FDF88}.Debug|x86.ActiveCfg = Debug|Win32
 		{0212A7C5-8D3F-443C-9EBC-1F28091FDF88}.Debug|x86.Build.0 = Debug|Win32
 		{0212A7C5-8D3F-443C-9EBC-1F28091FDF88}.Release|Any CPU.ActiveCfg = Release|Win32
@@ -341,7 +340,6 @@ Global
 		{FC05C557-C974-4CB3-9DA7-BB5476710E91}.Release|x86.Build.0 = Release|Any CPU
 		{75B1621F-EC51-4D77-BD7E-BEE576B3ADC9}.Debug|Any CPU.ActiveCfg = Debug|x86
 		{75B1621F-EC51-4D77-BD7E-BEE576B3ADC9}.Debug|x64.ActiveCfg = Debug|x64
-		{75B1621F-EC51-4D77-BD7E-BEE576B3ADC9}.Debug|x64.Build.0 = Debug|x64
 		{75B1621F-EC51-4D77-BD7E-BEE576B3ADC9}.Debug|x64.Deploy.0 = Debug|x64
 		{75B1621F-EC51-4D77-BD7E-BEE576B3ADC9}.Debug|x86.ActiveCfg = Debug|x86
 		{75B1621F-EC51-4D77-BD7E-BEE576B3ADC9}.Debug|x86.Build.0 = Debug|x86
@@ -355,7 +353,6 @@ Global
 		{75B1621F-EC51-4D77-BD7E-BEE576B3ADC9}.Release|x86.Deploy.0 = Release|x86
 		{493C7729-2F21-4198-AB09-BDF56BF501D3}.Debug|Any CPU.ActiveCfg = Debug|Win32
 		{493C7729-2F21-4198-AB09-BDF56BF501D3}.Debug|x64.ActiveCfg = Debug|x64
-		{493C7729-2F21-4198-AB09-BDF56BF501D3}.Debug|x64.Build.0 = Debug|x64
 		{493C7729-2F21-4198-AB09-BDF56BF501D3}.Debug|x86.ActiveCfg = Debug|Win32
 		{493C7729-2F21-4198-AB09-BDF56BF501D3}.Debug|x86.Build.0 = Debug|Win32
 		{493C7729-2F21-4198-AB09-BDF56BF501D3}.Release|Any CPU.ActiveCfg = Release|Win32
diff --git a/src/cswinrt/main.cpp b/src/cswinrt/main.cpp
index 75b31dfd2..4a1fff5cb 100644
--- a/src/cswinrt/main.cpp
+++ b/src/cswinrt/main.cpp
@@ -119,6 +119,7 @@ Where <spec> is one or more of:
         int result{};
         writer w;
 
+        /* Special case the usage exceptions to print CLI options */
         try
         {
             auto start = get_start_time();