diff --git a/Directory.Build.props b/Directory.Build.props
index 1be78d8e4ea4df..0b999b18d37dbe 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -88,9 +88,6 @@
 
     <!-- Resource naming bug: https://github.com/microsoft/msbuild/issues/4740 -->
     <EmbeddedResourceUseDependentUponConvention>false</EmbeddedResourceUseDependentUponConvention>
-
-    <!-- Enable NuGet static graph evaluation to optimize incremental restore: https://github.com/dotnet/sdk/pull/10794 -->
-    <!-- <RestoreUseStaticGraphEvaluation>true</RestoreUseStaticGraphEvaluation> -->
   </PropertyGroup>
 
   <PropertyGroup>
diff --git a/docs/coding-guidelines/project-guidelines.md b/docs/coding-guidelines/project-guidelines.md
index 5ab9a76c1573fd..e1ede65ea60b97 100644
--- a/docs/coding-guidelines/project-guidelines.md
+++ b/docs/coding-guidelines/project-guidelines.md
@@ -10,9 +10,9 @@ once before you can iterate and work on a given library project.
  - Netstandard Library - Copy to `bin\ref\netstandard2.0`
  - NetFx targeting pack - Copy to `bin\ref\net472`
 - Build targeting pack
- - Build src\libraries\ref.proj which builds all references assembly projects. For reference assembly project information see [ref](#ref)
+ - Build src\ref.builds which builds all references assembly projects. For reference assembly project information see [ref](#ref)
 - Build product
- - Build src\libraries\src.proj which builds all the source library projects. For source library project information see [src](#src).
+ - Build src\src.builds which builds all the source library projects. For source library project information see [src](#src).
 - Sign product
  - Build src\sign.proj
 
diff --git a/eng/Analyzers.props b/eng/Analyzers.props
index 034bb1b8e49c6c..534d38a5546ca3 100644
--- a/eng/Analyzers.props
+++ b/eng/Analyzers.props
@@ -1,8 +1,6 @@
 <Project>
   <PropertyGroup>
     <CodeAnalysisRuleset>$(MSBuildThisFileDirectory)CodeAnalysis.ruleset</CodeAnalysisRuleset>
-    <!-- Disable analyzers in sourcebuild -->
-    <EnableAnalyzers Condition="'$(DotNetBuildFromSource)' == 'true'">false</EnableAnalyzers>
   </PropertyGroup>
   <ItemGroup Condition="'$(EnableAnalyzers)' == 'true'">
     <PackageReference Include="Microsoft.DotNet.CodeAnalysis" Version="$(MicrosoftDotNetCodeAnalysisVersion)" PrivateAssets="all" IsImplicitlyDefined="true" />
diff --git a/eng/Build.props b/eng/Build.props
index 8827b98cd3642c..95f52b37593d49 100644
--- a/eng/Build.props
+++ b/eng/Build.props
@@ -15,7 +15,6 @@
       https://github.com/dotnet/arcade/issues/388
   -->
 
-  <!-- Import to have access to properties/items used both during the Arcade phase and in the repo. -->
   <Import Project="$(MSBuildThisFileDirectory)Configurations.props" />
   <Import Project="$(MSBuildThisFileDirectory)Subsets.props" />
 
@@ -77,12 +76,8 @@
     </ItemGroup>
 
     <MSBuild Projects="@(RepoTaskProjects)"
-             Properties="Configuration=Debug;Platform=AnyCPU;__BuildPhase=Restore"
-             Targets="Restore" />
-
-    <MSBuild Projects="@(RepoTaskProjects)"
-             Properties="Configuration=Debug;Platform=AnyCPU;__BuildPhase=Build"
-             Targets="Build" />
+             Properties="Configuration=Debug;Platform=AnyCPU"
+             Targets="Restore;Build"/>
 
     <WriteLinesToFile File="$(RepoTasksOutputFile)"
                       Lines="$(RepoTasksOutputFile)"
diff --git a/eng/Configurations.props b/eng/Configurations.props
index 2a6f427b15b852..12fe0471490d0d 100644
--- a/eng/Configurations.props
+++ b/eng/Configurations.props
@@ -1,24 +1,4 @@
 <Project>
-  <!--
-    This file contains properties and items which are used in both the Arcade
-    steps and in the repository.
-  -->
-
-  <PropertyGroup>
-    <LibrariesProjectRoot>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'src', 'libraries'))</LibrariesProjectRoot>
-    <CoreClrProjectRoot>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'src', 'coreclr'))</CoreClrProjectRoot>
-    <MonoProjectRoot>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'src', 'mono'))</MonoProjectRoot>
-    <InstallerProjectRoot>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'src', 'installer'))</InstallerProjectRoot>
-    <RepoToolsLocalDir>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'tools-local'))</RepoToolsLocalDir>
-    <RepoTasksDir>$([MSBuild]::NormalizeDirectory('$(RepoToolsLocalDir)', 'tasks'))</RepoTasksDir>
-    <IbcOptimizationDataDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsDir)', 'ibc'))</IbcOptimizationDataDir>
-    <XmlDocDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'docs'))</XmlDocDir>
-  </PropertyGroup>
-
-  <PropertyGroup>
-    <EnableNgenOptimization Condition="'$(EnableNgenOptimization)' == '' and '$(Configuration)' == 'Release'">true</EnableNgenOptimization>
-  </PropertyGroup>
-
   <!-- Honor the generic RuntimeConfiguration property. -->
   <PropertyGroup>
     <RuntimeConfiguration Condition="'$(RuntimeConfiguration)' == ''">$(Configuration)</RuntimeConfiguration>
diff --git a/eng/Subsets.props b/eng/Subsets.props
index 90346437faa14a..6939ee71af00b9 100644
--- a/eng/Subsets.props
+++ b/eng/Subsets.props
@@ -47,6 +47,15 @@
       artifacts to the test layout, then running the test subset.
   -->
 
+  <PropertyGroup>
+    <LibrariesProjectRoot>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'src', 'libraries'))</LibrariesProjectRoot>
+    <CoreClrProjectRoot>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'src', 'coreclr'))</CoreClrProjectRoot>
+    <MonoProjectRoot>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'src', 'mono'))</MonoProjectRoot>
+    <InstallerProjectRoot>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'src', 'installer'))</InstallerProjectRoot>
+    <RepoToolsLocalDir>$([MSBuild]::NormalizeDirectory('$(RepoRoot)', 'tools-local'))</RepoToolsLocalDir>
+    <RepoTasksDir>$([MSBuild]::NormalizeDirectory('$(RepoToolsLocalDir)', 'tasks'))</RepoTasksDir>
+  </PropertyGroup>
+
   <PropertyGroup>
     <DefaultSubsetCategories>libraries-installer-coreclr-mono</DefaultSubsetCategories>
     <DefaultInstallerSubsets>corehost-managed-depproj-pkgproj-bundle-installers-test</DefaultInstallerSubsets>
diff --git a/eng/Tools.props b/eng/Tools.props
index 999758d5f8f94a..4c399288ad250f 100644
--- a/eng/Tools.props
+++ b/eng/Tools.props
@@ -1,13 +1,39 @@
 <Project>
-  <!-- Import to have access to properties/items used both during the Arcade phase and in the repo. -->
-  <Import Project="$(MSBuildThisFileDirectory)Configurations.props" />
+  <PropertyGroup>
+    <MSBuildTreatWarningsAsErrors>false</MSBuildTreatWarningsAsErrors>
+    <EnableAnalyzers>true</EnableAnalyzers>
+  </PropertyGroup>
 
+  <!-- We need to import this props file which contains PackageReferences to analyzers so that
+       analyzer build assets are imported via the Tools generated props and targets -->
+  <Import Project="$(RepositoryEngineeringDir)Analyzers.props" Condition="Exists('$(RepositoryEngineeringDir)Analyzers.props') and '$(DotNetBuildFromSource)' != 'true'" />
+
+  <!-- source-built packages -->
   <ItemGroup>
+    <!-- arcade -->
+    <PackageReference Include="Microsoft.DotNet.GenFacades" Version="$(MicrosoftDotNetGenFacadesVersion)" />
     <PackageReference Include="Microsoft.DotNet.Build.Tasks.Packaging" Version="$(MicrosoftDotNetBuildTasksPackagingVersion)" />
+
+    <!-- coreclr -->
+    <!-- Download the package in the initial arcade restore step to work around race conditions when restoring an msbuild SDK. -->
+    <PackageDownload Include="Microsoft.NET.Sdk.IL" Version="[$(MicrosoftNETSdkILVersion)]" />
+
+    <!-- roslyn -->
+    <PackageReference Include="Microsoft.Net.Compilers.Toolset" Version="$(MicrosoftNetCompilersToolsetVersion)" PrivateAssets="all" IsImplicitlyDefined="true" />
+
+    <!-- mono -->
+    <PackageReference Include="illink.tasks" Version="$(ILLinkTasksVersion)" PrivateAssets="all" IsImplicitlyDefined="true" ExcludeAssets="build" GeneratePathProperty="true" />
+  </ItemGroup>
+
+  <!-- excluded from offline portion of source build -->
+  <ItemGroup Condition="'$(DotNetBuildOffline)' != 'true'">
+    <!-- arcade -->
+    <PackageReference Include="Microsoft.DotNet.GenAPI" Version="$(MicrosoftDotNetGenApiVersion)" />
   </ItemGroup>
 
   <!-- excluded from source build -->
   <ItemGroup Condition="'$(DotNetBuildFromSource)' != 'true'">
+    <PackageReference Include="Microsoft.DotNet.ApiCompat" Version="$(MicrosoftDotNetApiCompatVersion)" />
     <PackageReference Include="Microsoft.DotNet.Build.Tasks.Feed" Version="$(MicrosoftDotNetBuildTasksFeedVersion)" />
     <PackageReference Include="Microsoft.DotNet.VersionTools.Tasks" Version="$(MicrosoftDotNetVersionToolsTasksVersion)" />
 
diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index 6174024211e1dd..e2b20bc565a85c 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -38,13 +38,13 @@
       <Uri>https://github.com/dotnet/arcade</Uri>
       <Sha>421b20fb860907c45673de791177e3fd61402197</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.CodeAnalysis" Version="5.0.0-beta.20156.4">
+    <Dependency Name="Microsoft.DotNet.CodeAnalysis" Version="5.0.0-beta.20153.1">
       <Uri>https://github.com/dotnet/arcade</Uri>
       <Sha>421b20fb860907c45673de791177e3fd61402197</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk" Version="5.0.0-beta.20155.2">
+    <Dependency Name="Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk" Version="5.0.0-beta.20153.1">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>bc4fa8e7149769db4efd466f160417a32b11f0bf</Sha>
+      <Sha>421b20fb860907c45673de791177e3fd61402197</Sha>
     </Dependency>
     <Dependency Name="Microsoft.DotNet.RemoteExecutor" Version="5.0.0-beta.20153.1">
       <Uri>https://github.com/dotnet/arcade</Uri>
diff --git a/eng/Versions.props b/eng/Versions.props
index eadba345483640..e7bd40414e24d9 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -19,6 +19,10 @@
     <UsingToolMicrosoftNetCompilers>true</UsingToolMicrosoftNetCompilers>
     <UsingToolIbcOptimization>true</UsingToolIbcOptimization>
     <UsingToolXliff>false</UsingToolXliff>
+    <!-- Paths used during restore -->
+    <EnableNgenOptimization Condition="'$(EnableNgenOptimization)' == '' and '$(Configuration)' == 'Release'">true</EnableNgenOptimization>
+    <IbcOptimizationDataDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsDir)', 'ibc'))</IbcOptimizationDataDir>
+    <XmlDocDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'docs'))</XmlDocDir>
     <!-- Blob storage container that has the "Latest" channel to publish to. -->
     <ContainerName>dotnet</ContainerName>
     <ChecksumContainerName>$(ContainerName)</ChecksumContainerName>
@@ -56,7 +60,7 @@
     <!-- Arcade dependencies -->
     <MicrosoftDotNetApiCompatVersion>5.0.0-beta.20153.1</MicrosoftDotNetApiCompatVersion>
     <MicrosoftDotNetBuildTasksFeedVersion>5.0.0-beta.20153.1</MicrosoftDotNetBuildTasksFeedVersion>
-    <MicrosoftDotNetCodeAnalysisVersion>5.0.0-beta.20156.4</MicrosoftDotNetCodeAnalysisVersion>
+    <MicrosoftDotNetCodeAnalysisVersion>5.0.0-beta.20153.1</MicrosoftDotNetCodeAnalysisVersion>
     <MicrosoftDotNetGenAPIVersion>5.0.0-beta.20153.1</MicrosoftDotNetGenAPIVersion>
     <MicrosoftDotNetGenFacadesVersion>5.0.0-beta.20153.1</MicrosoftDotNetGenFacadesVersion>
     <MicrosoftDotNetXUnitExtensionsVersion>5.0.0-beta.20153.1</MicrosoftDotNetXUnitExtensionsVersion>
diff --git a/eng/codeAnalysis.targets b/eng/codeAnalysis.targets
new file mode 100644
index 00000000000000..de4eb79cd35db1
--- /dev/null
+++ b/eng/codeAnalysis.targets
@@ -0,0 +1,51 @@
+<Project>
+  <Import Condition="Exists($(AnalyzerPropsFile)) and '$(EnableAnalyzers)' == 'true'" Project="$(AnalyzerPropsFile)" />
+
+  <!-- This target is executed when building a project and EnableAnalyzers property is set to true. 
+  It will populate the Analyzer item that is passed to the compiler with the analyzers restored
+  as package references in Tools.props. Those analyzers will be saved in a props file -> artifacts\toolset\Common\Tools.Analyzers.props.
+  So in order to add a new analyzer just need to add a package reference in Tools.props to the package containing it.
+  *
+  This target also provides filtering for specific type of projects through to Items.
+  - <AnalyzersToInclude> will include only the specified analyzers and will ignore the others that where restored.
+  - <AnalyzersToExclude> will exclude the specified analyzers from the restored analyzers, but will preserve the others.
+  **The values in these Items are the name of the analyzers' dll.
+  **These to Items are mutually exclusive, so only 1 should be set at a time.
+  Example of usage:
+  <AnalyzersToInclude Condition="$(IsTestProject)" Include="Xunit.Analyzers" /> will only include Xunit analyzers.
+  <AnalyzersToExclude Condition="$(IsSourceProject)" Include="Xunit.Analyzers" /> will include all analyzers but Xunit analyzer. -->
+
+  <Target Name="CalculateAnalyzersForBuildTime">
+    <ItemGroup>
+      <Analyzer Include="@(ResolvedAnalyzer)" />
+    </ItemGroup>
+
+    <Warning Text="AnalyzersToExclude and AnalyzersToInclude shouldn't be set together, they are mutually exclusive." Condition="'@(AnalyzersToExclude)' != '' and '@(AnalyzersToInclude)' != ''" />
+
+    <ItemGroup Condition="'@(AnalyzersToExclude)' != '' or '@(AnalyzersToInclude)' != ''">
+      <_AnalyzersToFileName Include="@(Analyzer -> '%(FileName)')">
+        <OriginalIdentity>%(Identity)</OriginalIdentity>
+      </_AnalyzersToFileName>
+    </ItemGroup>
+
+    <ItemGroup Condition="'@(AnalyzersToExclude)' != ''">
+      <_AnalyzersToRemove Include="@(_AnalyzersToFileName)" Condition="'@(AnalyzersToExclude)' == '@(_AnalyzersToFileName)' and '%(Identity)' != ''" />
+      <Analyzer Remove="@(_AnalyzersToRemove -> '%(OriginalIdentity)')" />
+    </ItemGroup>
+
+    <ItemGroup Condition="'@(AnalyzersToInclude)' != ''">
+      <_AnalyzersToRemove Include="@(_AnalyzersToFileName)" Exclude="@(AnalyzersToInclude)" />
+      <_missingAnalyzersToInclude Include="@(AnalyzersToInclude)" Exclude="@(_AnalyzersToFileName)" />
+      <Analyzer Remove="@(_AnalyzersToRemove -> '%(OriginalIdentity)')" />
+    </ItemGroup>
+
+    <Error Text="Couldn't find analyzer to include with values: @(_missingAnalyzersToInclude)" Condition="'@(_missingAnalyzersToInclude)' != '' and '@(_missingAnalyzersToInclude)' != 'None'" />
+  </Target>
+
+  <PropertyGroup Condition="'$(EnableAnalyzers)' == 'true'">
+  	<ResolveReferencesDependsOn>
+  	  $(ResolveReferencesDependsOn);
+  	  CalculateAnalyzersForBuildTime;
+  	</ResolveReferencesDependsOn>
+  </PropertyGroup>
+</Project>
\ No newline at end of file
diff --git a/eng/docker/build-docker-sdk.ps1 b/eng/docker/build-docker-sdk.ps1
index af1943a0d49dce..76c1ce7b414070 100755
--- a/eng/docker/build-docker-sdk.ps1
+++ b/eng/docker/build-docker-sdk.ps1
@@ -18,7 +18,8 @@ if ($buildWindowsContainers)
   # Due to size concerns, we don't currently do docker builds on windows.
   # Build on the host machine, then simply copy artifacts to the target docker image.
   # This should result in significantly lower build times, for now.
-  & "$REPO_ROOT_DIR/build.cmd" -ci -subsetcategory coreclr-libraries -runtimeconfiguration release -c $configuration
+  & "$REPO_ROOT_DIR/coreclr.cmd" -c Release
+  & "$REPO_ROOT_DIR/libraries.cmd" -ci -c $configuration -runtimeConfiguration release
   
   # Dockerize the build artifacts
   docker build --tag $imageName `
diff --git a/eng/docker/libraries-sdk.linux.Dockerfile b/eng/docker/libraries-sdk.linux.Dockerfile
index fce6381e71028a..efba4fb7c309d4 100644
--- a/eng/docker/libraries-sdk.linux.Dockerfile
+++ b/eng/docker/libraries-sdk.linux.Dockerfile
@@ -8,7 +8,8 @@ WORKDIR /repo
 COPY . .
 
 ARG CONFIGURATION=Release
-RUN ./build.sh -ci -subsetcategory coreclr-libraries -runtimeconfiguration release -c $CONFIGURATION
+RUN ./src/coreclr/build.sh -release -skiptests -clang9 && \
+    ./libraries.sh -c $CONFIGURATION -runtimeconfiguration release
 
 FROM $SDK_BASE_IMAGE as target
 
diff --git a/eng/pipelines/libraries/enterprise/linux.yml b/eng/pipelines/libraries/enterprise/linux.yml
index 017ca39dbb0cce..4cf1c7ded3827c 100644
--- a/eng/pipelines/libraries/enterprise/linux.yml
+++ b/eng/pipelines/libraries/enterprise/linux.yml
@@ -26,7 +26,7 @@ variables:
   - name: enterpriseTestsSetup
     value: $(sourcesRoot)/Common/tests/System/Net/EnterpriseTests/setup
   - name: containerRunTestsCommand
-    value: /repo/.dotnet/dotnet build /t:test
+    value: /repo/.dotnet/dotnet build /t:test --no-restore
   - name: containerLibrariesRoot
     value: /repo/src/libraries
 
@@ -50,7 +50,7 @@ steps:
   displayName: Test linuxclient connection to web server
 
 - bash: |
-    docker exec linuxclient bash -c '/repo/build.sh -subsetcategory coreclr-libraries -runtimeconfiguration release -ci'
+    docker exec linuxclient bash -c '/repo/src/coreclr/build.sh -release -skipnuget -clang9 && /repo/libraries.sh /p:CoreCLRConfiguration=Release'
   displayName: Build product sources
 
 - bash: |
diff --git a/eng/restore/repoRestore.props b/eng/restore/repoRestore.props
index 3d6a393519d7f1..204c23d1de0b95 100644
--- a/eng/restore/repoRestore.props
+++ b/eng/restore/repoRestore.props
@@ -28,4 +28,4 @@
     <ComputeNETCoreBuildOutputFiles>false</ComputeNETCoreBuildOutputFiles>
     <GenerateRuntimeConfigurationFiles>false</GenerateRuntimeConfigurationFiles>
   </PropertyGroup>
-</Project>
+</Project>
\ No newline at end of file
diff --git a/eng/restore/repoRestore.targets b/eng/restore/repoRestore.targets
index a430b67fee1fff..d99f198e1a5fbd 100644
--- a/eng/restore/repoRestore.targets
+++ b/eng/restore/repoRestore.targets
@@ -4,6 +4,8 @@
     <RestoreProjectStyle Condition="'$(MSBuildProjectExtension)' != '.depproj'">Unknown</RestoreProjectStyle>
   </PropertyGroup>
 
+  <Import Project="$(RepositoryEngineeringDir)codeAnalysis.targets" />
+
   <PropertyGroup>
     <!-- Nuget will normally disable all generated imports as part of a restore to avoid 
          non-determinism where first restore changes a subsequent restore,
diff --git a/global.json b/global.json
index cd9ec82380b6f0..b92f7803faf034 100644
--- a/global.json
+++ b/global.json
@@ -12,7 +12,7 @@
     "python": "2.7.15"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk": "5.0.0-beta.20156.4",
+    "Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk": "5.0.0-beta.20153.1",
     "Microsoft.DotNet.Arcade.Sdk": "5.0.0-beta.20153.1",
     "Microsoft.DotNet.Build.Tasks.SharedFramework.Sdk": "5.0.0-beta.20153.1",
     "Microsoft.DotNet.Helix.Sdk": "5.0.0-beta.20153.1",
diff --git a/src/libraries/Directory.Build.props b/src/libraries/Directory.Build.props
index 37c82ea5a46e87..4ff8a6be977978 100644
--- a/src/libraries/Directory.Build.props
+++ b/src/libraries/Directory.Build.props
@@ -119,6 +119,12 @@
     <IsShipping Condition="'$(IsTestProject)' == 'true'">false</IsShipping>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <EnableProjectRestore Condition="'$(IsTestProject)' == 'true'">true</EnableProjectRestore>
+  </PropertyGroup>
+
+  <Import Condition="'$(EnableProjectRestore)' != 'true'" Project="$(RepositoryEngineeringDir)restore\repoRestore.props" />
+
   <!-- Common repo directories -->
   <PropertyGroup>
     <!-- Need to try and keep the same logic as the native builds as we need this for packaging -->
@@ -140,14 +146,6 @@
     <ApiCompatExcludeAttributeList>$(RepositoryEngineeringDir)DefaultGenApiDocIds.txt</ApiCompatExcludeAttributeList>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(IsTestProject)' != 'true'">
-    <PackageReference Include="Microsoft.DotNet.Build.Tasks.Packaging" Version="$(MicrosoftDotNetBuildTasksPackagingVersion)" PrivateAssets="all" IsImplicitlyDefined="true" />
-    <PackageReference Include="Microsoft.DotNet.GenFacades" Version="$(MicrosoftDotNetGenFacadesVersion)" PrivateAssets="all" IsImplicitlyDefined="true" />
-    <PackageReference Include="Microsoft.DotNet.ApiCompat" Condition="'$(DotNetBuildFromSource)' != 'true'" Version="$(MicrosoftDotNetApiCompatVersion)" PrivateAssets="all" IsImplicitlyDefined="true" />
-    <PackageReference Include="Microsoft.DotNet.GenAPI" Condition="'$(DotNetBuildOffline)' != 'true'" Version="$(MicrosoftDotNetGenApiVersion)" PrivateAssets="all" IsImplicitlyDefined="true" />
-    <PackageReference Include="illink.tasks" Version="$(ILLinkTasksVersion)" PrivateAssets="all" IsImplicitlyDefined="true" ExcludeAssets="build" GeneratePathProperty="true" />
-  </ItemGroup>
-
   <PropertyGroup>
     <_runtimeOSVersionIndex>$(RuntimeOS.IndexOfAny(".-0123456789"))</_runtimeOSVersionIndex>
     <_runtimeOSFamily Condition="'$(_runtimeOSVersionIndex)' != '-1'">$(RuntimeOS.SubString(0, $(_runtimeOSVersionIndex)))</_runtimeOSFamily>
@@ -172,7 +170,6 @@
     <ToolRuntimeRID Condition="'$(RuntimeOS)' == 'webassembly' and '$(TargetOS)' == 'Windows_NT'">win-x64</ToolRuntimeRID>
     <ToolRuntimeRID Condition="'$(RuntimeOS)' == 'webassembly' and '$(TargetOS)' != 'Windows_NT' and $(_buildingInOSX)">osx-x64</ToolRuntimeRID>
     <ToolRuntimeRID Condition="'$(RuntimeOS)' == 'webassembly' and '$(TargetOS)' != 'Windows_NT' and !$(_buildingInOSX)">linux-x64</ToolRuntimeRID>
-    <MicrosoftNetCoreIlasmPackageRuntimeId>$(ToolRuntimeRID)</MicrosoftNetCoreIlasmPackageRuntimeId>
 
     <!-- support cross-targeting by choosing a RID to restore when running on a different machine that what we're build for -->
     <_portableOS Condition="'$(TargetOS)' == 'Unix' and '$(_runtimeOSFamily)' != 'osx' and '$(_runtimeOSFamily)' != 'FreeBSD' and '$(_runtimeOS)' != 'linux-musl'">linux</_portableOS>
@@ -271,10 +268,10 @@
     <Features>strict;nullablePublicOnly</Features>
     <WarningLevel>4</WarningLevel>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
-    <!-- We decided to keep this disabled by default: https://github.com/dotnet/runtime/issues/15152 -->
+    <!-- We decided to keep this disabled by default to see some history of way have a look at https://github.com/dotnet/corefx/issues/3140 -->
     <CheckForOverflowUnderflow>false</CheckForOverflowUnderflow>
     <GenFacadesIgnoreBuildAndRevisionMismatch>true</GenFacadesIgnoreBuildAndRevisionMismatch>
-    <EnableAnalyzers Condition="'$(EnableAnalyzers)' == '' and '$(IsSourceProject)' == 'true' and '$(MSBuildProjectExtension)' != '.ilproj'">true</EnableAnalyzers>
+    <EnableAnalyzers Condition="'$(EnableProjectRestore)' == 'true' and '$(IsSourceProject)' == 'true' and '$(MSBuildProjectExtension)' != '.ilproj'">true</EnableAnalyzers>
   </PropertyGroup>
 
   <!-- Set up some common paths -->
@@ -299,6 +296,7 @@
     <NetStandard20RefPath>$([MSBuild]::NormalizeDirectory('$(RefRootPath)', 'netstandard2.0'))</NetStandard20RefPath>
     <NetStandard21RefPath>$([MSBuild]::NormalizeDirectory('$(RefRootPath)', 'netstandard2.1'))</NetStandard21RefPath>
     <NetFxRefPath>$([MSBuild]::NormalizeDirectory('$(RefRootPath)', '$(NetFrameworkCurrent)'))</NetFxRefPath>
+    <ILAsmToolPath>$([MSBuild]::NormalizeDirectory('$(ArtifactsToolsetDir)', 'ilasm'))</ILAsmToolPath>
 
     <!-- Helix properties -->
     <OSPlatformConfig>$(TargetOS).$(Platform).$(Configuration)</OSPlatformConfig>
@@ -337,12 +335,6 @@
   <!-- Import it at the end of the props file to override the OutputPath for reference assemblies and use common directory props -->
   <Import Project="$(RepositoryEngineeringDir)referenceAssemblies.props" />
 
-  <PropertyGroup>
-    <EnableProjectRestore Condition="'$(IsSourceProject)' == 'true' or '$(IsReferenceAssembly)' == 'true' or '$(IsTestProject)' == 'true'">true</EnableProjectRestore>
-  </PropertyGroup>
-
-  <Import Condition="'$(EnableProjectRestore)' != 'true'" Project="$(RepositoryEngineeringDir)restore\repoRestore.props" />
-
   <PropertyGroup>
     <EnableDefaultItems>false</EnableDefaultItems>
     <EmbedUntrackedSources>true</EmbedUntrackedSources>
diff --git a/src/libraries/Directory.Build.targets b/src/libraries/Directory.Build.targets
index f019b5bd21a6af..659009ab0dbe2f 100644
--- a/src/libraries/Directory.Build.targets
+++ b/src/libraries/Directory.Build.targets
@@ -113,6 +113,7 @@
 
   <Import Sdk="Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk" Project="Sdk.targets" />
   <Import Condition="'$(EnableProjectRestore)' != 'true'" Project="$(RepositoryEngineeringDir)restore\repoRestore.targets" />
+
   <Import Project="$(RepositoryEngineeringDir)referenceFromRuntime.targets" />
   <Import Project="$(RepositoryEngineeringDir)illink.targets" />
   <Import Project="$(RepositoryEngineeringDir)notSupported.SourceBuild.targets" Condition="'$(DotNetBuildFromSource)' == 'true'" />
diff --git a/src/libraries/Microsoft.VisualBasic.Core/src/Microsoft.VisualBasic.Core.vbproj b/src/libraries/Microsoft.VisualBasic.Core/src/Microsoft.VisualBasic.Core.vbproj
index e8774341649cad..436ecca9fbe2d5 100644
--- a/src/libraries/Microsoft.VisualBasic.Core/src/Microsoft.VisualBasic.Core.vbproj
+++ b/src/libraries/Microsoft.VisualBasic.Core/src/Microsoft.VisualBasic.Core.vbproj
@@ -18,8 +18,6 @@
     <RootNamespace />
     <!-- Disable this as it seems to break windows builds for now. -->
     <DocumentationFile />
-    <!-- No plans to fix the analyzer issues. -->
-    <EnableAnalyzers>false</EnableAnalyzers>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppCurrent)-Windows_NT</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
diff --git a/src/libraries/System.Net.Http/src/PinvokeAnalyzerExceptionList.analyzerdata b/src/libraries/System.Net.Http/src/PInvokeAnalyzerExceptionList.analyzerdata
similarity index 100%
rename from src/libraries/System.Net.Http/src/PinvokeAnalyzerExceptionList.analyzerdata
rename to src/libraries/System.Net.Http/src/PInvokeAnalyzerExceptionList.analyzerdata
diff --git a/src/libraries/System.Runtime.WindowsRuntime/ref/System.Runtime.WindowsRuntime.csproj b/src/libraries/System.Runtime.WindowsRuntime/ref/System.Runtime.WindowsRuntime.csproj
index ee65f5e9eff934..08655bbddfe08f 100644
--- a/src/libraries/System.Runtime.WindowsRuntime/ref/System.Runtime.WindowsRuntime.csproj
+++ b/src/libraries/System.Runtime.WindowsRuntime/ref/System.Runtime.WindowsRuntime.csproj
@@ -18,13 +18,13 @@
     <Compile Include="System.Runtime.WindowsRuntime.Manual.cs" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetsNetCoreApp)' == 'true'">
-    <PackageReference Include="Microsoft.TargetingPack.Private.WinRT" Version="$(MicrosoftTargetingPackPrivateWinRTVersion)" PrivateAssets="all" />
+    <ProjectReference Include="$(LibrariesProjectRoot)restore\winrt\winrt.depproj" />
     <ProjectReference Include="..\..\mscorlib.WinRT-Facade\ref\mscorlib.WinRT-Facade.csproj" />
     <ProjectReference Include="..\..\System.Runtime\ref\System.Runtime.csproj" />
     <ProjectReference Include="..\..\System.Runtime.Extensions\ref\System.Runtime.Extensions.csproj" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetsNetStandard)' == 'true'">
-    <PackageReference Include="Microsoft.TargetingPack.Private.WinRT" Version="$(MicrosoftTargetingPackPrivateWinRTVersion)" PrivateAssets="all" />
+    <ProjectReference Include="$(LibrariesProjectRoot)restore\winrt\winrt.depproj" />
     <ProjectReference Include="..\..\mscorlib.WinRT-Facade\ref\mscorlib.WinRT-Facade.csproj" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.Runtime.WindowsRuntime/src/System.Runtime.WindowsRuntime.csproj b/src/libraries/System.Runtime.WindowsRuntime/src/System.Runtime.WindowsRuntime.csproj
index 147afba607288f..60f7f32e4794b7 100644
--- a/src/libraries/System.Runtime.WindowsRuntime/src/System.Runtime.WindowsRuntime.csproj
+++ b/src/libraries/System.Runtime.WindowsRuntime/src/System.Runtime.WindowsRuntime.csproj
@@ -15,6 +15,18 @@
     <GeneratePlatformNotSupportedAssemblyMessage>SR.PlatformNotSupported_WindowsRuntime</GeneratePlatformNotSupportedAssemblyMessage>
     <GeneratePlatformNotSupportedAssemblyWithGlobalPrefix>true</GeneratePlatformNotSupportedAssemblyWithGlobalPrefix>
   </PropertyGroup>
+  <ItemGroup Condition="'$(TargetsNetCoreApp)' == 'true'">
+    <ReferenceFromRuntime Include="System.Private.CoreLib" />
+    <Reference Include="mscorlib" />
+    <Reference Include="Windows" />
+    <ProjectReference Include="$(LibrariesProjectRoot)restore\winrt\winrt.depproj" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == '$(NetCoreAppCurrent)'">
+    <ProjectReference Include="..\..\System.Runtime\src\System.Runtime.csproj" />
+    <ProjectReference Include="..\..\System.Runtime.Extensions\src\System.Runtime.Extensions.csproj" />
+    <ProjectReference Include="..\..\System.Runtime.InteropServices.WindowsRuntime\src\System.Runtime.InteropServices.WindowsRuntime.csproj" />
+    <ProjectReference Include="..\..\System.ObjectModel\src\System.ObjectModel.csproj" />
+  </ItemGroup>
   <ItemGroup Condition="'$(TargetsNetCoreApp)' == 'true'">
     <Compile Include="System\IO\StreamOperationAsyncResult.cs" />
     <Compile Include="System\Runtime\InteropServices\WindowsRuntime\MarshalingHelpers.cs" />
@@ -82,24 +94,12 @@
       <Link>Common\System\HexConverter.cs</Link>
     </Compile>
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetsNetCoreApp)' == 'true'">
-    <ReferenceFromRuntime Include="System.Private.CoreLib" />
-    <Reference Include="mscorlib" />
-    <Reference Include="Windows" />
-    <PackageReference Include="Microsoft.TargetingPack.Private.WinRT" Version="$(MicrosoftTargetingPackPrivateWinRTVersion)" PrivateAssets="all" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetFramework)' == '$(NetCoreAppCurrent)'">
-    <ProjectReference Include="..\..\System.Runtime\src\System.Runtime.csproj" />
-    <ProjectReference Include="..\..\System.Runtime.Extensions\src\System.Runtime.Extensions.csproj" />
-    <ProjectReference Include="..\..\System.Runtime.InteropServices.WindowsRuntime\src\System.Runtime.InteropServices.WindowsRuntime.csproj" />
-    <ProjectReference Include="..\..\System.ObjectModel\src\System.ObjectModel.csproj" />
-  </ItemGroup>
   <ItemGroup Condition="'$(TargetsNetStandard)' == 'true'">
     <Reference Include="System.Runtime" />
     <Reference Include="System.IO" />
     <Reference Include="System.Threading.Tasks" />
     <Reference Include="System.Resources.ResourceManager" />
-    <PackageReference Include="Microsoft.TargetingPack.Private.WinRT" Version="$(MicrosoftTargetingPackPrivateWinRTVersion)" PrivateAssets="all" />
+    <ProjectReference Include="$(LibrariesProjectRoot)restore\winrt\winrt.depproj" />
     <ProjectReference Include="..\..\mscorlib.WinRT-Facade\ref\mscorlib.WinRT-Facade.csproj" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.Runtime.WindowsRuntime/tests/System.Runtime.WindowsRuntime.Tests.csproj b/src/libraries/System.Runtime.WindowsRuntime/tests/System.Runtime.WindowsRuntime.Tests.csproj
index 8633fffda010c5..dab72ed0560b0e 100644
--- a/src/libraries/System.Runtime.WindowsRuntime/tests/System.Runtime.WindowsRuntime.Tests.csproj
+++ b/src/libraries/System.Runtime.WindowsRuntime/tests/System.Runtime.WindowsRuntime.Tests.csproj
@@ -18,6 +18,6 @@
     <Compile Include="Windows\UI\ColorTests.cs" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.TargetingPack.Private.WinRT" Version="$(MicrosoftTargetingPackPrivateWinRTVersion)" PrivateAssets="all" />
+    <Reference Include="Windows" />
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/build.proj b/src/libraries/build.proj
index 0e00e66aea4501..8da5cf9b63eb6e 100644
--- a/src/libraries/build.proj
+++ b/src/libraries/build.proj
@@ -11,32 +11,21 @@
     <BuildDependsOn Condition="'$(BuildManaged)' == 'true' and '$(BuildTests)' != 'only'">$(BuildDependsOn);BuildManaged</BuildDependsOn>
     <BuildDependsOn Condition="'$(BuildPackages)' == 'true' and '$(BuildTests)' != 'only'">$(BuildDependsOn);Pack</BuildDependsOn>
     <BuildDependsOn Condition="'$(BuildTests)' != ''">$(BuildDependsOn);BuildTests</BuildDependsOn>
-
-    <RestoreAll Condition="'$(RestoreAll)' == '' and '$(ContinuousIntegrationBuild)' == 'true'">true</RestoreAll>
   </PropertyGroup>
 
   <Import Project="Directory.Build.targets" />
 
   <Target Name="Restore" DependsOnTargets="GenerateRuntimeOSPropsFile">
     <ItemGroup Condition="'$(DirectoryToBuild)' == ''">
-      <_RestoreBuildProjects Include="$(MSBuildThisFileDirectory)restore\dirs.proj" />
-      <_RestoreProjects Include="@(_RestoreBuildProjects)" />
+      <_RestoreProjects Include="$(MSBuildThisFileDirectory)restore\dirs.proj" Build="true" />
     </ItemGroup>
-
-    <ItemGroup Condition="'$(RestoreAll)' == 'true'">
-      <_RestoreProjects Include="$(MSBuildThisFileDirectory)dirs.proj"  />
-      <_RestoreProjects Include="$(MSBuildThisFileDirectory)tests.proj" Condition="'$(DotNetBuildFromSource)' != 'true'" />
-      <_RestoreProjects Include="$(MSBuildThisFileDirectory)packages.proj" />
+    
+    <ItemGroup Condition="'$(DotNetBuildFromSource)' != 'true'">
+      <_RestoreProjects Include="$(MSBuildThisFileDirectory)tests.proj" Build="false" />
     </ItemGroup>
 
-    <MSBuild Projects="@(_RestoreProjects)"
-             Targets="Restore"
-             Properties="__BuildPhase=Restore"
-             BuildInParallel="true" />
-
-    <MSBuild Projects="@(_RestoreBuildProjects)"
-             Properties="__BuildPhase=Build"
-             Targets="Build" />
+    <MSBuild Projects="@(_RestoreProjects)" Targets="Restore" Properties="$(ProjectProperties)" />
+    <MSBuild Projects="@(_RestoreProjects)" Condition="'%(Build)' != 'false'" Properties="$(ProjectProperties)" />
   </Target>
 
   <Target Name="BuildNative">
@@ -44,7 +33,7 @@
       <_BuildNativeProjects Include="$(MSBuildThisFileDirectory)Native\build-native.proj" />
     </ItemGroup>
 
-    <MSBuild Projects="@(_BuildNativeProjects)" />
+    <MSBuild Projects="@(_BuildNativeProjects)" Properties="$(ProjectProperties)" />
   </Target>
 
   <Target Name="BuildManaged">
@@ -52,15 +41,7 @@
       <_BuildMangedProjects Include="$(MSBuildThisFileDirectory)dirs.proj" />
     </ItemGroup>
 
-    <!-- Only restore if there was no upfront restore. -->
-    <MSBuild Projects="@(_BuildMangedProjects)"
-             Condition="'$(RestoreAll)' != 'true'"
-             Properties="__BuildPhase=Restore"
-             Targets="Restore" />
-
-    <MSBuild Projects="@(_BuildMangedProjects)"
-             Properties="__BuildPhase=Build"
-             Targets="Build" />
+    <MSBuild Projects="@(_BuildMangedProjects)" Properties="$(ProjectProperties)" />
   </Target>
 
   <Target Name="BuildTests">
@@ -68,15 +49,9 @@
       <_TestProjects Include="$(MSBuildThisFileDirectory)tests.proj" />
     </ItemGroup>
 
-    <!-- Only restore if there was no upfront restore. -->
     <MSBuild Projects="@(_TestProjects)"
-             Condition="'$(RestoreAll)' != 'true'"
-             Properties="__BuildPhase=Restore"
-             Targets="Restore" />
-
-    <MSBuild Projects="@(_TestProjects)"             
-             Properties="__BuildPhase=Build"
-             Targets="Build" />
+             Targets="Build"
+             Properties="$(ProjectProperties)" />
   </Target>
 
   <Target Name="Test">
@@ -85,23 +60,16 @@
     </ItemGroup>
 
     <MSBuild Projects="@(_TestProjects)"
-             Targets="Test" />
+             Targets="Test"
+             Properties="$(ProjectProperties)" />
   </Target>
 
   <Target Name="Pack">
     <ItemGroup>
-      <_PackProjects Include="$(MSBuildThisFileDirectory)packages.proj" />
+      <_PackProjects Include="$(MSBuildThisFileDirectory)packages.builds" />
     </ItemGroup>
 
-    <!-- Only restore if there was no upfront restore. -->
-    <MSBuild Projects="@(_PackProjects)"
-             Condition="'$(RestoreAll)' != 'true'"
-             Properties="__BuildPhase=Restore"
-             Targets="Restore" />
-
-    <MSBuild Projects="@(_PackProjects)"
-             Targets="Build"
-             Properties="__BuildPhase=Build" />
+    <MSBuild Projects="@(_PackProjects)" Properties="$(ProjectProperties)" />
   </Target>
 
   <Target Name="Build" DependsOnTargets="$(BuildDependsOn)" />
diff --git a/src/libraries/dirs.proj b/src/libraries/dirs.proj
index d03d5892fe7920..2b9534d5965a81 100644
--- a/src/libraries/dirs.proj
+++ b/src/libraries/dirs.proj
@@ -1,35 +1,26 @@
 <Project>
-  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.props" />
+  <Import Project="$(MSBuildThisFileDirectory)Directory.Build.props" />
 
+  <!-- required to build the projects in their specified order -->
   <PropertyGroup>
-    <TargetFramework>$(BuildTargetFramework)</TargetFramework>
+    <SerializeProjects>true</SerializeProjects>
   </PropertyGroup>
 
   <ItemGroup Condition="'$(DirectoryToBuild)' == ''">
-    <ProjectReference Include="ref.proj" />
-    <ProjectReference Include="Native\native-binplace.proj" />
-    <ProjectReference Include="src.proj" />
-    <ProjectReference Include="shims\manual\*.csproj" />
-    <ProjectReference Include="shims\ApiCompat.proj" Condition="'$(DotNetBuildFromSource)' != 'true' and '$(BuildTargetFramework)' == '$(NetCoreAppCurrent)'" />
-    <ProjectReference Include="pretest.proj" Condition="'$(DotNetBuildFromSource)' != 'true' and '$(BuildAllConfigurations)' != 'true'" />
+    <Project Include="ref.builds" />
+    <Project Include="shims\generated\*.csproj" />
+    <Project Include="Native\native-binplace.proj" />
+    <Project Include="src.builds" />
+    <Project Include="shims\manual\*.csproj" />
+    <Project Include="shims\ApiCompat.proj" Condition="'$(DotNetBuildFromSource)' != 'true' and '$(BuildTargetFramework)' == '$(NetCoreAppCurrent)'" />
+    <Project Include="pretest.proj" Condition="'$(DotNetBuildFromSource)' != 'true' and '$(BuildAllConfigurations)' != 'true'" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(DirectoryToBuild)' != ''">
-    <ProjectReference Include="ref.proj" />
-    <ProjectReference Include="src.proj" />
+    <Project Include="ref.builds" />
+    <Project Include="src.builds" />
   </ItemGroup>
 
-  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
+  <Import Project="$(MSBuildThisFileDirectory)dir.traversal.targets" />
   
-  <!--
-    Ordering matters! Overwriting the Build target after the Sdk.targets import.
-    BuildInParallel false is required to build the projects in their specified order.
-  -->
-  <Target Name="Build" DependsOnTargets="BuildAllProjects" />
-  <Target Name="BuildAllProjects">
-    <MSBuild Targets="Build"
-             Projects="@(ProjectReference)"
-             Properties="BuildAllProjects=true"
-             ContinueOnError="ErrorAndStop" />
-  </Target>
-</Project>
+</Project>
\ No newline at end of file
diff --git a/src/libraries/packages.proj b/src/libraries/packages.builds
similarity index 71%
rename from src/libraries/packages.proj
rename to src/libraries/packages.builds
index 9e62eb26d72bff..ab33fce628208e 100644
--- a/src/libraries/packages.proj
+++ b/src/libraries/packages.builds
@@ -1,22 +1,23 @@
 <Project>
-  <PropertyGroup>
-    <EnableProjectRestore>true</EnableProjectRestore>
-  </PropertyGroup>
-
-  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.props" />
+  <Import Project="$(MSBuildThisFileDirectory)Directory.Build.props" />
 
-  <PropertyGroup>
-    <TargetFramework>$(BuildTargetFramework)</TargetFramework>
-    <AdditionalBuildTargetFrameworks Condition="'$(DotNetBuildFromSource)' == 'true'">$(AdditionalBuildTargetFrameworks);package-$(Configuration)</AdditionalBuildTargetFrameworks>
+  <PropertyGroup Condition="'$(DotNetBuildFromSource)' == 'true'">
+    <AdditionalBuildTargetFrameworks>$(AdditionalBuildTargetFrameworks);package-$(Configuration)</AdditionalBuildTargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup Condition="'$(SkipManagedPackageBuild)' != 'true'">
-    <ProjectReference Include="$(PkgDir)*\*.builds" />
-    <ProjectReference Include="*\pkg\**\*.pkgproj" Condition="'$(BuildAllConfigurations)' == 'true' or '$(DotNetBuildFromSource)' == 'true'" />
+    <Project Include="$(PkgDir)*\*.builds" >
+      <AdditionalProperties>$(AdditionalProperties)</AdditionalProperties>
+    </Project>
+    <Project Include="*\pkg\**\*.pkgproj" Condition="'$(BuildAllConfigurations)' == 'true' OR '$(DotNetBuildFromSource)' == 'true'">
+      <AdditionalProperties>$(AdditionalProperties)</AdditionalProperties>
+    </Project>
   </ItemGroup>
 
   <!-- Need the PackageIndexFile file property from baseline.props -->
-  <Import Project="$(RepositoryEngineeringDir)restore\harvestPackages.targets" />
+  <Import Project="$(PkgDir)baseline\baseline.props" />
+
+  <UsingTask TaskName="UpdatePackageIndex" AssemblyFile="$(PackagingTaskDir)Microsoft.DotNet.Build.Tasks.Packaging.dll"/>
 
   <!--
     Updates the package index to mark all packages we are building that can go stable as stable.
@@ -68,6 +69,8 @@
       Overwrite="true" />
   </Target>
 
+  <Import Project="$(MSBuildThisFileDirectory)dir.traversal.targets" />
+
   <Target Name="SetAzureDevOpsVariableForBuiltPackages"
           Condition="'$(ContinuousIntegrationBuild)' == 'true'"
           AfterTargets="BuildAllProjects">
@@ -77,16 +80,4 @@
 
     <Message Condition="'@(_PackageReports)' != ''" Importance="High" Text="##vso[task.setvariable variable=_librariesBuildProducedPackages]true" />
   </Target>
-
-  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
-
-  <!-- Ordering matters! Overwriting the Build and Test target after the Sdk.targets import. -->
-  <Target Name="Build" DependsOnTargets="BuildAllProjects" />
-  <Target Name="BuildAllProjects">
-    <MSBuild Targets="Build"
-             Projects="@(ProjectReference)"
-             Properties="BuildAllProjects=true"
-             BuildInParallel="true"
-             ContinueOnError="ErrorAndStop" />
-  </Target>
 </Project>
diff --git a/src/libraries/pretest.proj b/src/libraries/pretest.proj
index 5b5cb13dd2490c..317bf140a39af2 100644
--- a/src/libraries/pretest.proj
+++ b/src/libraries/pretest.proj
@@ -2,15 +2,16 @@
   <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.props" />
 
   <PropertyGroup>
-    <TargetFramework>$(BuildTargetFramework)</TargetFramework>
     <BuildDependsOnTargets>GenerateLaunchSettingsFiles</BuildDependsOnTargets>
     <BuildDependsOnTargets Condition="'$(BinplaceTestSharedFramework)' == 'true'">$(BuildDependsOnTargets);GenerateTestSharedFrameworkDepsFile</BuildDependsOnTargets>
     <BuildDependsOnTargets Condition="'$(PlatformManifestFile)' != ''">$(BuildDependsOnTargets);GenerateFileVersionProps</BuildDependsOnTargets>
+    <TargetFrameworkIdentifier>netcoreapp</TargetFrameworkIdentifier>
+    <TargetFrameworkVersion>5.0</TargetFrameworkVersion>
   </PropertyGroup>
 
   <ItemGroup>
     <!-- This is necessary as inside VS project references that aren't part of the sln aren't built. -->
-    <ProjectReference Include="$(CommonTestPath)CoreFx.Private.TestUtilities\CoreFx.Private.TestUtilities.csproj" />
+    <Project Include="$(CommonTestPath)\CoreFx.Private.TestUtilities\CoreFx.Private.TestUtilities.csproj" />
   </ItemGroup>
 
   <!-- Microsoft.XmlSerializer.Generator should not be marked as a platform item and be copy-local instead. -->
@@ -57,7 +58,6 @@
       <_TestProjectRootDir>$(LibrariesProjectRoot)</_TestProjectRootDir>
       <_TestProjectRootDir Condition="'$(DirectoryToBuild)'!=''">$(DirectoryToBuild)</_TestProjectRootDir>
     </PropertyGroup>
-
     <ItemGroup>
       <!-- Keep in sync with pattern for test projects in tests.proj -->
       <TestProjects Include="$(_TestProjectRootDir)*\tests\**\*.Tests.csproj" />
@@ -65,7 +65,7 @@
 
     <MSBuild Projects="@(TestProjects)"
              Targets="GenerateLaunchSettingsFile"
-             ContinueOnError="ErrorAndStop" />
+             ContinueOnError="ErrorAndContinue" />
   </Target>
 
   <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
@@ -73,9 +73,15 @@
   <Target Name="Build"
           Condition="'$(SkipPrepareTest)' != 'true'"
           DependsOnTargets="GenerateLaunchSettingsFiles;GenerateTestSharedFrameworkDepsFile;GenerateFileVersionProps">
+
     <MSBuild Targets="Build"
-             Projects="@(ProjectReference)"
+             Projects="@(Project)"
+             Properties="TargetFramework=$(BuildTargetFramework);%(Project.AdditionalProperties)"
              BuildInParallel="true"
              ContinueOnError="ErrorAndStop" />
+
+    <!-- Given we ErrorAndContinue we need to propagate the error if the overall task failed -->
+    <Error Condition="'$(MSBuildLastTaskResult)' == 'false'" />
+
   </Target>
 </Project>
diff --git a/src/libraries/ref.builds b/src/libraries/ref.builds
new file mode 100644
index 00000000000000..9bef0a6e4edbab
--- /dev/null
+++ b/src/libraries/ref.builds
@@ -0,0 +1,14 @@
+<Project DefaultTargets="Build" >
+  <Import Project="$(MSBuildThisFileDirectory)Directory.Build.props" />
+
+  <ItemGroup Condition="'$(RuntimeFlavor)' == 'Mono'"> 
+    <ProjectExclusions Include="$(MSBuildThisFileDirectory)\System.Utf8String.Experimental\ref\System.Utf8String.Experimental.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Project Condition="'$(DirectoryToBuild)' == ''" Include="$(MSBuildThisFileDirectory)*\ref\*.*proj" Exclude="@(ProjectExclusions)" />
+    <Project Condition="'$(DirectoryToBuild)' != ''" Include="$(DirectoryToBuild)\ref\*.*proj" />
+  </ItemGroup>
+
+  <Import Project="$(MSBuildThisFileDirectory)dir.traversal.targets" />
+</Project>
diff --git a/src/libraries/ref.proj b/src/libraries/ref.proj
deleted file mode 100644
index 99037969eaadb3..00000000000000
--- a/src/libraries/ref.proj
+++ /dev/null
@@ -1,30 +0,0 @@
-<Project>
-  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.props" />
-
-  <PropertyGroup>
-    <TargetFramework>$(BuildTargetFramework)</TargetFramework>
-  </PropertyGroup>
-
-  <ItemGroup Condition="'$(RuntimeFlavor)' == 'Mono'"> 
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)\System.Utf8String.Experimental\ref\System.Utf8String.Experimental.csproj" />
-  </ItemGroup>
-
-  <ItemGroup Condition="'$(DirectoryToBuild)' == ''">
-    <ProjectReference Include="$(MSBuildThisFileDirectory)*\ref\*.*proj" Exclude="@(ProjectExclusions)" />
-    <ProjectReference Include="shims\generated\*.csproj" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(DirectoryToBuild)' != ''">
-    <ProjectReference Include="$(DirectoryToBuild)\ref\*.*proj" />
-  </ItemGroup>
-
-  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
-  
-  <!-- Ordering matters! Overwriting the Build target after the Sdk.targets import. -->
-  <Target Name="Build" DependsOnTargets="BuildAllProjects" />
-  <Target Name="BuildAllProjects">
-    <MSBuild Targets="Build"
-             Projects="@(ProjectReference)"
-             Properties="BuildAllProjects=true"
-             ContinueOnError="ErrorAndStop" />
-  </Target>
-</Project>
diff --git a/src/libraries/restore/analyzers/analyzers.depproj b/src/libraries/restore/analyzers/analyzers.depproj
new file mode 100644
index 00000000000000..27fad4d37cff1d
--- /dev/null
+++ b/src/libraries/restore/analyzers/analyzers.depproj
@@ -0,0 +1,27 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <EnableBinPlacing>false</EnableBinPlacing>
+    <EnableAnalyzers>true</EnableAnalyzers>
+    <Language>C#</Language>
+    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <!-- 
+      Microsoft.CodeAnalysis.Common shouldn't be referenced directly but is needed by the analyzer depproj restore.
+      TODO: Remove when project restore is enabled for non test projects: https://github.com/dotnet/corefx/issues/41512.
+    -->
+    <PackageReference Include="Microsoft.CodeAnalysis.Common" Version="3.4.0-beta2-final" PrivateAssets="all" />
+  </ItemGroup>
+
+  <UsingTask TaskName="Microsoft.DotNet.Arcade.Sdk.SaveItems" AssemblyFile="$(ArcadeSdkBuildTasksAssembly)" />
+
+  <Target Name="GenerateAnalyzersPropsFile"
+          AfterTargets="ResolveLockFileAnalyzers">
+
+    <SaveItems Condition="'@(Analyzer)' != ''"
+               ItemName="ResolvedAnalyzer"
+               Items="@(Analyzer)"
+               File="$(AnalyzerPropsFile)" />
+  </Target>
+</Project>
diff --git a/src/libraries/restore/dirs.proj b/src/libraries/restore/dirs.proj
index ee2162758d1e64..d54794d38db3ee 100644
--- a/src/libraries/restore/dirs.proj
+++ b/src/libraries/restore/dirs.proj
@@ -1,14 +1,15 @@
 <Project>
   <Import Project="Directory.Build.props" />
 
-  <PropertyGroup>
-    <TargetFramework>$(BuildTargetFramework)</TargetFramework>
-  </PropertyGroup>
-
   <ItemGroup>
-    <Project Include="netcoreapp/netcoreapp.depproj" Condition="'$(BuildAllConfigurations)' == 'true'" />
+    <Project Condition="'$(DotNetBuildFromSource)' != 'true'" Include="analyzers/analyzers.depproj" />
+
+    <!-- Build for all configurations -->
+    <Project Condition="'$(BuildAllConfigurations)' == 'true'" Include="netcoreapp/netcoreapp.depproj" />
     <Project Include="netstandard/netstandard.depproj" />
     <Project Include="netfx/netfx.depproj" />
+    <Project Include="tools/tools.depproj" />
+    <Project Include="harvestPackages/harvestPackages.depproj" />
     <Project Include="binplacePackages/binplacePackages.depproj" />
   </ItemGroup>
 
diff --git a/eng/restore/harvestPackages.targets b/src/libraries/restore/harvestPackages/harvestPackages.depproj
similarity index 54%
rename from eng/restore/harvestPackages.targets
rename to src/libraries/restore/harvestPackages/harvestPackages.depproj
index d6f6f98019f1cc..2ae20ecda6e67c 100644
--- a/eng/restore/harvestPackages.targets
+++ b/src/libraries/restore/harvestPackages/harvestPackages.depproj
@@ -1,14 +1,15 @@
-<Project InitialTargets="AddPackageDownload">
+<Project InitialTargets="AddPackageDownload" Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <PackagingTaskAssembly>$(NuGetPackageRoot)microsoft.dotnet.build.tasks.packaging\$(MicrosoftDotNetBuildTasksPackagingVersion)\tools\</PackagingTaskAssembly>
-    <PackagingTaskAssembly Condition="'$(MSBuildRuntimeType)' == 'core'">$(PackagingTaskAssembly)netcoreapp2.1\</PackagingTaskAssembly>
-    <PackagingTaskAssembly Condition="'$(MSBuildRuntimeType)' != 'core'">$(PackagingTaskAssembly)net472\</PackagingTaskAssembly>
-    <PackagingTaskAssembly>$(PackagingTaskAssembly)Microsoft.DotNet.Build.Tasks.Packaging.dll</PackagingTaskAssembly>
+    <TargetFrameworks>netstandard2.0</TargetFrameworks>
   </PropertyGroup>
 
-  <Import Project="$(LibrariesProjectRoot)pkg\baseline\baseline.props" />
+  <Import Project="$(PkgDir)baseline/baseline.props" />
+
+  <!-- only restore this project during the build, don't copy any of it's packages
+       The sole purpose of this project is to download packages that can be examined
+       for harvesting binaries & support. -->
+  <Target Name="Build" DependsOnTargets="RestorePackages" />
 
-  <UsingTask TaskName="GetLastStablePackage" AssemblyFile="$(PackagingTaskAssembly)"/>
   <Target Name="AddPackageDownload">
     <ItemGroup>
       <_AllPkgProjs Include="$(LibrariesProjectRoot)*\pkg\**\*.pkgproj" />
@@ -19,10 +20,10 @@
     </ItemGroup>
 
     <GetLastStablePackage
-      LatestPackages="@(_AllPkgProjsToPackageIdentity)"
-      PackageIndexes="$(PackageIndexFile)"
-      DoNotAllowVersionsFromSameRelease="true">
-      <Output TaskParameter="LastStablePackages" ItemName="_PackageDownload" />
+        LatestPackages="@(_AllPkgProjsToPackageIdentity)"
+        PackageIndexes="$(PackageIndexFile)"
+        DoNotAllowVersionsFromSameRelease="true">
+        <Output TaskParameter="LastStablePackages" ItemName="_PackageDownload" />
     </GetLastStablePackage>
 
     <!-- Allow to override package download and versions in case there is already a PackageDownload set -->
@@ -39,4 +40,5 @@
       </PackageDownload>
     </ItemGroup>
   </Target>
+
 </Project>
\ No newline at end of file
diff --git a/src/libraries/restore/tools/tools.depproj b/src/libraries/restore/tools/tools.depproj
new file mode 100644
index 00000000000000..f2e32a3773b8b6
--- /dev/null
+++ b/src/libraries/restore/tools/tools.depproj
@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputPath>$(ILAsmToolPath)</OutputPath>
+    <EnableBinPlacing>false</EnableBinPlacing>
+    <RuntimeIdentifier>$(ToolRuntimeRID)</RuntimeIdentifier>
+    <NoWarn>$(NoWarn);NU1603;NU1605</NoWarn>
+    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NETCore.ILAsm">
+      <Version>$(MicrosoftNETCoreILAsmVersion)</Version>
+    </PackageReference>
+    <PackageReference Include="Microsoft.NETCore.ILDAsm">
+      <Version>$(MicrosoftNETCoreILAsmVersion)</Version>
+    </PackageReference>
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/src/libraries/restore/winrt/winrt.depproj b/src/libraries/restore/winrt/winrt.depproj
new file mode 100644
index 00000000000000..fb99977c302e51
--- /dev/null
+++ b/src/libraries/restore/winrt/winrt.depproj
@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <AssemblyName>Windows</AssemblyName>
+    <TargetExt>.winmd</TargetExt>
+    <!-- don't binplace for netstandard since the netstandard ref path is used for API compat and assumed to be 
+         implemented by all frameworks that support it.  Instead require projectreference to this project -->
+    <BinPlaceRef Condition="'$(TargetsNetStandard)' != 'true'">true</BinPlaceRef>
+    <NuGetDeploySourceItem>Reference</NuGetDeploySourceItem>
+    <TargetFrameworks>netcoreapp3.0;$(netcoreappCurrent);netstandard1.0</TargetFrameworks>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.TargetingPack.Private.WinRT">
+      <Version>1.0.5</Version>
+    </PackageReference>
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/src/libraries/shims/ApiCompat.proj b/src/libraries/shims/ApiCompat.proj
index db4c9fe1d756ef..a340a3d1a5aecd 100644
--- a/src/libraries/shims/ApiCompat.proj
+++ b/src/libraries/shims/ApiCompat.proj
@@ -1,12 +1,9 @@
-<Project>
-  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.props" />
+<Project DefaultTargets="Build">
 
-  <PropertyGroup>
-    <TargetFramework>$(BuildTargetFramework)</TargetFramework>
-  </PropertyGroup>
+  <Import Project="Directory.Build.props" />
 
   <PropertyGroup>
-    <ApiCompatTarget>$(TargetFramework)</ApiCompatTarget>
+    <ApiCompatTarget>$(BuildTargetFramework)</ApiCompatTarget>
     <ApiCompatTarget Condition="$(BuildTargetFramework.Contains('netcoreapp'))">netcoreapp</ApiCompatTarget>
     <ApiCompatResponseFile>$(IntermediateOutputPath)/apicompat.rsp</ApiCompatResponseFile>
     <ApiCompatBaselineFile>$(MSBuildThisFileDirectory)ApiCompatBaseline.$(ApiCompatTarget).netfx461.txt</ApiCompatBaselineFile>
@@ -101,12 +98,11 @@
 
   </Target>
 
-  <Target Name="CleanAdditionalFiles" AfterTargets="Clean">
+  <Target Name="Build" DependsOnTargets="RunApiCompat" />
+  <Target Name="Clean">
     <RemoveDir Directories="$(BaseIntermediateOutputPath)" />
   </Target>
+  <Target Name="Rebuild" DependsOnTargets="Clean;Build" />
 
-  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
-
-  <!-- Ordering matters! Overwriting the Build target after the Sdk.targets import. -->
-  <Target Name="Build" DependsOnTargets="RunApiCompat" />
+  <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.targets))" />
 </Project>
diff --git a/src/libraries/shims/Directory.Build.props b/src/libraries/shims/Directory.Build.props
index 768825eb3e775b..790b6126ca80de 100644
--- a/src/libraries/shims/Directory.Build.props
+++ b/src/libraries/shims/Directory.Build.props
@@ -1,7 +1,4 @@
 <Project>
-  <PropertyGroup>
-    <EnableProjectRestore>true</EnableProjectRestore>
-  </PropertyGroup>
   <Import Project="..\Directory.Build.props" />
 
   <Import Project="netfxreference.props" />
diff --git a/src/libraries/src.builds b/src/libraries/src.builds
new file mode 100644
index 00000000000000..5903b7fd7a10af
--- /dev/null
+++ b/src/libraries/src.builds
@@ -0,0 +1,21 @@
+<Project DefaultTargets="Build" TreatAsLocalProperty="AdditionalBuildTargetFrameworks">
+  <Import Project="$(MSBuildThisFileDirectory)Directory.Build.props" />
+
+  <ItemGroup Condition="'$(RuntimeFlavor)' == 'Mono'"> 
+    <ProjectExclusions Include="$(MSBuildThisFileDirectory)\System.Utf8String.Experimental\src\System.Utf8String.Experimental.csproj" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(DirectoryToBuild)' == ''">
+    <Project Include="$(MSBuildThisFileDirectory)*\src\*.csproj" Exclude="@(ProjectExclusions)" />
+    <Project Include="$(MSBuildThisFileDirectory)*\src\*.ilproj" Exclude="@(ProjectExclusions)" />
+    <Project Include="$(MSBuildThisFileDirectory)*\src\*.vbproj" Exclude="@(ProjectExclusions)" />
+    <!-- Explicitly include the runtime.depproj project here to correctly set up the test host. -->
+    <Project Include="$(MSBuildThisFileDirectory)restore\runtime\runtime.depproj" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(DirectoryToBuild)' != ''">
+    <Project Include="$(DirectoryToBuild)\src\*.*proj" />
+  </ItemGroup>
+
+  <Import Project="$(MSBuildThisFileDirectory)dir.traversal.targets" />
+</Project>
diff --git a/src/libraries/src.proj b/src/libraries/src.proj
deleted file mode 100644
index d2d0ec88d23df0..00000000000000
--- a/src/libraries/src.proj
+++ /dev/null
@@ -1,34 +0,0 @@
-<Project>
-  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.props" />
-
-  <PropertyGroup>
-    <TargetFramework>$(BuildTargetFramework)</TargetFramework>
-  </PropertyGroup>
-
-  <ItemGroup Condition="'$(RuntimeFlavor)' == 'Mono'"> 
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)\System.Utf8String.Experimental\src\System.Utf8String.Experimental.csproj" />
-  </ItemGroup>
-
-  <ItemGroup Condition="'$(DirectoryToBuild)' == ''">
-    <ProjectReference Include="$(MSBuildThisFileDirectory)*\src\*.csproj" Exclude="@(ProjectExclusions)" />
-    <ProjectReference Include="$(MSBuildThisFileDirectory)*\src\*.ilproj" Exclude="@(ProjectExclusions)" />
-    <ProjectReference Include="$(MSBuildThisFileDirectory)*\src\*.vbproj" Exclude="@(ProjectExclusions)" />
-    <!-- Explicitly include the runtime.depproj project here to correctly set up the test host. -->
-    <ProjectReference Include="$(MSBuildThisFileDirectory)restore\runtime\runtime.depproj" />
-  </ItemGroup>
-
-  <ItemGroup Condition="'$(DirectoryToBuild)' != ''">
-    <ProjectReference Include="$(DirectoryToBuild)\src\*.*proj" />
-  </ItemGroup>
-
-  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
-  
-  <!-- Ordering matters! Overwriting the Build target after the Sdk.targets import. -->
-  <Target Name="Build" DependsOnTargets="BuildAllProjects" />
-  <Target Name="BuildAllProjects">
-    <MSBuild Targets="Build"
-             Projects="@(ProjectReference)"
-             Properties="BuildAllProjects=true"
-             ContinueOnError="ErrorAndStop" />
-  </Target>
-</Project>
diff --git a/src/libraries/tests.proj b/src/libraries/tests.proj
index 1a32a6b477c382..d47a26ac972b8b 100644
--- a/src/libraries/tests.proj
+++ b/src/libraries/tests.proj
@@ -1,9 +1,9 @@
-<Project>
+<Project InitialTargets="IncludeProjectReferences">
   <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.props" />
   <Import Project="$(RepositoryEngineeringDir)coverage.props" Condition="'$(EnableCoverageSupport)' == 'true'" />
 
   <PropertyGroup>
-    <TargetFramework>$(BuildTargetFramework)</TargetFramework>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(EnableCoverageSupport)' == 'true'">
@@ -14,16 +14,22 @@
 
   <ItemGroup Condition="'$(BuildAllConfigurations)' != 'true'">
     <!-- We currently only test with C# projects. -->
-    <ProjectReference Condition="'$(DirectoryToBuild)' != ''" Include="$(DirectoryToBuild)\**\*.Tests.csproj" />
-    <ProjectReference Condition="'$(SkipTestRestore)' != 'true' and '$(DirectoryToBuild)' == ''" Include="$(MSBuildThisFileDirectory)*\tests\**\*.Tests.csproj" Exclude="@(ProjectExclusions)" />
-    <ProjectReference Condition="'$(SkipTestRestore)' == 'true' and '$(DirectoryToBuild)' == ''" Include="$(CommonTestPath)CoreFx.Private.TestUtilities\CoreFx.Private.TestUtilities.csproj" />
-    <ProjectReference Remove="$(CommonTestPath)System\Net\Prerequisites\**\*.csproj" />
+    <Project Condition="'$(DirectoryToBuild)' != ''" Include="$(DirectoryToBuild)\**\*.Tests.csproj" />
+    <Project Condition="'$(SkipTestRestore)' != 'true' and '$(DirectoryToBuild)' == ''" Include="$(MSBuildThisFileDirectory)*\tests\**\*.Tests.csproj" Exclude="@(ProjectExclusions)" />
+    <Project Condition="'$(SkipTestRestore)' == 'true' and '$(DirectoryToBuild)' == ''" Include="$(CommonTestPath)CoreFx.Private.TestUtilities\CoreFx.Private.TestUtilities.csproj" />
+    <Project Remove="$(CommonTestPath)System\Net\Prerequisites\**\*.csproj" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(BuildAllConfigurations)' == 'true'">
-    <ProjectReference Include="$(MSBuildThisFileDirectory)pkg\test\testPackages.proj" />
+    <Project Include="$(MSBuildThisFileDirectory)pkg\test\testPackages.proj" />
   </ItemGroup>
 
+  <Target Name="IncludeProjectReferences">
+    <ItemGroup>
+      <ProjectReference Include="@(Project)" />
+    </ItemGroup>
+  </Target>
+
   <Target Name="GenerateCoverageReport"
           Condition="'$(EnableCoverageSupport)' == 'true' and '$(SkipCoverageReport)' != 'true'"
           AfterTargets="TestAllProjects"
@@ -35,14 +41,16 @@
   <Import Project="$(RepositoryEngineeringDir)coverage.targets" Condition="'$(EnableCoverageSupport)' == 'true'" />
   <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
   
-  <!-- Ordering matters! Overwriting the Build and Test target after the Sdk.targets import. -->
   <Target Name="Build" DependsOnTargets="BuildAllProjects" />
   <Target Name="BuildAllProjects">
     <MSBuild Targets="Build"
-             Projects="@(ProjectReference)"
-             Properties="BuildAllProjects=true"
+             Projects="@(Project)"
+             Properties="BuildAllProjects=true;%(Project.AdditionalProperties)"
              BuildInParallel="true"
              ContinueOnError="ErrorAndStop" />
+
+    <!-- Given we ErrorAndContinue we need to propagate the error if the overall task failed -->
+    <Error Condition="'$(MSBuildLastTaskResult)' == 'false'" />
   </Target>
 
   <Target Name="Test" DependsOnTargets="TestAllProjects" />
@@ -50,13 +58,13 @@
     <!-- To Serialize we use msbuild's batching functionality '%' to force it to batch all similar projects with the same identity
          however since the project names are unique it will essentially force each to run in its own batch -->
     <MSBuild Targets="Test"
-             Projects="@(ProjectReference)"
+             Projects="@(Project)"
              Condition="'$(SerializeProjects)' == 'true' and '%(Identity)' != ''"
              Properties="TestAllProjects=true"
              ContinueOnError="ErrorAndContinue" />
 
     <MSBuild Targets="Test"
-             Projects="@(ProjectReference)"
+             Projects="@(Project)"
              Condition="'$(SerializeProjects)' != 'true'"
              Properties="TestAllProjects=true"
              BuildInParallel="true"
@@ -65,4 +73,5 @@
     <!-- Given we ErrorAndContinue we need to propagate the error if the overall task failed -->
     <Error Condition="'$(MSBuildLastTaskResult)' == 'false'" />
   </Target>
+
 </Project>