WiX Toolset v4-preview.0 is available. For more information, see Rob’s blog post on the matter.
Building WiX v4 is quite a bit easier than it was building WiX v3. That said, there are still some steps you need to take that prevent it from being a purely out-of-the-box experience.
One problem you might run into – I know, because I did – is that if you have an alias or the MSBuild autoresponse file MSBuild.rsp configured, you might run into problems building WiX v4. Specifically, in my case, I had an alias that automatically enabled multiproc builds using the
/maxcpucount switch. Though we intend to make the build more multiproc-friendly, today it’s driven by batch files at each top-level directory and objects to building with the
/m switch. I fixed my alias and all is well.