I'm not sure if anyone will care about this, but I figured I should mention it somewhere.
With the release of Wine Mono 4.7.0 today, the source tree now ships with a Vagrantfile, which can be used with Vagrant to create a virtual machine that can build the project. This was the environment used to create the msi package, and I plan to continue using it this way for future releases.
Previously, the official build environment was my work PC, which means there was always the possibility that upgrading or changing it would have some effect on the official packages.
I don't know if this is useful for anyone else, but I figure that an easy way to create a build environment, along with the complete documentation of that environment which we get as a side-effect, can only be a good thing.
This is not a replacement for building on real hardware. I only plan to use it to make official builds, not for development, and I still want to hear about any issues people encounter while trying to do the build on their own systems.