save the contents of the NuGet package cache as a build artifact

azure-pipelines.yml

@@ -187,6 +187,14 @@ stages:
               publishLocation: Container
             continueOnError: true
             condition: eq(variables['_testKind'], 'testFSharpQA')
+          - task: PublishBuildArtifacts@1
+            displayName: Publish NuGet cache contents
+            inputs:
+              PathtoPublish: '$(Build.SourcesDirectory)\artifacts\NugetPackageRootContents'
+              ArtifactName: 'NuGetPackageContents Windows $(_testKind)'
+              publishLocation: Container
+            continueOnError: true
+            condition: always()
 
         # Linux
         - job: Linux
@@ -208,6 +216,14 @@ stages:
               searchFolder: '$(Build.SourcesDirectory)/artifacts/TestResults/$(_BuildConfig)'
             continueOnError: true
             condition: always()
+          - task: PublishBuildArtifacts@1
+            displayName: Publish NuGet cache contents
+            inputs:
+              PathtoPublish: '$(Build.SourcesDirectory)/artifacts/NugetPackageRootContents'
+              ArtifactName: 'NuGetPackageContents Linux'
+              publishLocation: Container
+            continueOnError: true
+            condition: always()
 
         # MacOS
         - job: MacOS
@@ -229,6 +245,14 @@ stages:
               searchFolder: '$(Build.SourcesDirectory)/artifacts/TestResults/$(_BuildConfig)'
             continueOnError: true
             condition: always()
+          - task: PublishBuildArtifacts@1
+            displayName: Publish NuGet cache contents
+            inputs:
+              PathtoPublish: '$(Build.SourcesDirectory)/artifacts/NugetPackageRootContents'
+              ArtifactName: 'NuGetPackageContents Mac'
+              publishLocation: Container
+            continueOnError: true
+            condition: always()
 
         # Source Build Linux
         - job: SourceBuild_Linux
@@ -239,6 +263,14 @@ stages:
             clean: true
           - script: ./eng/cibuild.sh --configuration Release /p:DotNetBuildFromSource=true /p:FSharpSourceBuild=true
             displayName: Build
+          - task: PublishBuildArtifacts@1
+            displayName: Publish NuGet cache contents
+            inputs:
+              PathtoPublish: '$(Build.SourcesDirectory)/artifacts/NugetPackageRootContents'
+              ArtifactName: 'NuGetPackageContents SourceBuild_Linux'
+              publishLocation: Container
+            continueOnError: true
+            condition: always()
 
         # Source Build Windows
         - job: SourceBuild_Windows
@@ -249,6 +281,14 @@ stages:
             clean: true
           - script: eng\CIBuild.cmd -configuration Release -noSign /p:DotNetBuildFromSource=true /p:FSharpSourceBuild=true
             displayName: Build
+          - task: PublishBuildArtifacts@1
+            displayName: Publish NuGet cache contents
+            inputs:
+              PathtoPublish: '$(Build.SourcesDirectory)\artifacts\NugetPackageRootContents'
+              ArtifactName: 'NuGetPackageContents SourceBuild_Windows'
+              publishLocation: Container
+            continueOnError: true
+            condition: always()
 
         # Up-to-date
         - job: UpToDate_Windows

eng/AfterSolutionBuild.targets

@@ -0,0 +1,18 @@
+<Project>
+
+  <!-- Used as a diagnostic tool to view the state of the NuGet package cache as it existed immediately after a restore/build. -->
+
+  <ItemGroup>
+    <PackageRootFiles Include="$(NuGetPackageRoot)/**" />
+  </ItemGroup>
+
+  <Target Name="_DumpPackageRootDirectoryListing"
+          AfterTargets="Build">
+    <PropertyGroup>
+      <PackageRootArtifactDirectory>$(ArtifactsDir)NugetPackageRootContents</PackageRootArtifactDirectory>
+      <PackageRootContentsFile>$(PackageRootArtifactDirectory)/package_contents.txt</PackageRootContentsFile>
+    </PropertyGroup>
+    <MakeDir Directories="$(PackageRootArtifactDirectory)" Condition="!Exists('$(PackageRootArtifactDirectory)')" />
+    <WriteLinesToFile File="$(PackageRootContentsFile)" Lines="@(PackageRootFiles)" />
+  </Target>
+</Project>