It doesn't work right now because the Phone tools SDK isn't installed on our build agent images.  We've been talking with the phone tools team about this.  The blocker that we have is that the Phone tools SDK can't be installed on a server edition of the OS (it's blocked).  Add to that the fact that you can only run server OS editions on cloud environments and you have a recipe for "no-worky".  The Phone tools SDK team has commited to doing the work to unblock the Phone SDK on a server OS edition.  I don't yet have a timeframe for that but I'm guessing within the next couple of months.

Brian