Build VS 2015 extension on build server without VS installed?

Question

Is it possible to build a Visual Studio 2015 extension project on a build server (TeamCity agent) without Visual Studio installed? What kind of SDK do we need to install?

At the moment we receive the following error message:

error MSB4019: The imported project "C:\Program Files (x86)\MSBuild\Microsoft\Portable\v4.6\Microsoft.Portable.CSharp.targets" was not found. Confirm that the path in the declaration is correct, and that the file exists on disk.

So there is definitely some kind of SDK missing.

Answer 1

Microsoft.VSSDK.BuildTools

Contains targets and tools to enable the building of managed VSIX projects without VSSDK MSI installed. Only for VS 2015 and onwards

Additional packages that may be of interest: https://www.nuget.org/profiles/VisualStudioExtensibility

Answer 2

Using @weir's answer almost worked - the project built successfully, but it failed to produce a VSIX container at the end. For some reason the Nuget package hadn't added the necessary Import to the .csproj to bring in the VsSDK.targets, so the VSIX targets were missing and never got executed.

Here are the steps which worked for me:

1. Edit the VSIX project .csproj file, and remove Import Project="$(VSToolsPath)\VSSDK\Microsoft.VsSDK.targets" Condition="'$(VSToolsPath)' != ''" />. This will fail on the build server where the VSSDK doesn't exist in the VSToolsPath.
2. In the VS2015 IDE, open the Nuget Package Manager for the project, and install Microsoft.VSSDK.BuildTools (I used v14.3.25407)
3. Back in the .csproj file, find the import which the Nuget package added, e.g. <Import Project="..\packages\Microsoft.VSSDK.BuildTools.14.3.25407\build\Microsoft.VSSDK.BuildTools.targets" .../> and add another one below it for the VsSDK.targets file (inside the tools directory), <Import Project="..\packages\Microsoft.VSSDK.BuildTools.14.3.25407\tools\vssdk\Microsoft.VsSDK.targets" .../>