How do I enable C# 7 builds in Team Foundation Server 2015?

Question

We have Team Foundation Server (TFS) 2015 installed on-premises. We would like to use Visual Studio 2017 to take advantage of the latest C# language features. We are not ready to upgrade to TFS 2017. What are the steps required to allow the latest C# language features to build in TFS 2015?

Answer 1

I didn't follow these steps exactly, but based on what I have learned, I think they would have worked:

1. Install Visual Studio 2017 Build Tools on the XAML Build Configuration server
2. Add these lines to the TFSBuildServiceHost.exe.config file:

  <configSections>
    <section name="msbuildToolsets" type="Microsoft.Build.Evaluation.ToolsetConfigurationSection, Microsoft.Build.Utilities.Core, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" requirePermission="false" />
  </configSections>
  <msbuildToolsets>
    <toolset toolsVersion="15.0">
      <property name="MSBuildToolsPath" value="C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\MSBuild\15.0\Bin" />
    </toolset>
    <toolset toolsVersion="latest">
      <property name="MSBuildToolsPath" value="C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\MSBuild\15.0\Bin" />
    </toolset>
  </msbuildToolsets>

C:\Program Files\Microsoft Team Foundation Server 14.0\Tools\TFSBuildServiceHost.exe.config

(I never would have figure that out without this post. Thank you jonesy2488!)

3. Restart the XAML Build Configuration service.
4. Change the XAML Build Process Template to include the ToolVersion="15.0" parameter:

<mtba:RunMSBuild DisplayName="Run MSBuild" OutputLocation="[OutputLocation]" CleanBuild="[CleanBuild]" CommandLineArguments="[String.Format(&quot;/p:SkipInvalidConfigurations=true {0}&quot;, AdvancedBuildSettings.GetValue(Of String)(&quot;MSBuildArguments&quot;, String.Empty))]" ConfigurationsToBuild="[ConfigurationsToBuild]" ProjectsToBuild="[ProjectsToBuild]" ToolVersion="15.0" ToolPlatform="[AdvancedBuildSettings.GetValue(Of String)(&quot;MSBuildPlatform&quot;, &quot;Auto&quot;)]" RunCodeAnalysis="[AdvancedBuildSettings.GetValue(Of String)(&quot;RunCodeAnalysis&quot;, &quot;AsConfigured&quot;)]" />