No, a cross build on a linux host.  I've not really tested any of my windows builds, though, and mostly only ever build daemon and motogame, not qt, just for the sake of making sure they build at all.

I have not seriously tried to build anything directly on windows in quite a few years.

EDIT: Yah, right now windows motogame doesn't build with whatever gcc3.x my ming is using.  I'll look into that more after I clean up the map search.