First, this is only my idea, because I see wxFormBuilder use the build bot for the nightly build, see its github homepage:
wxFormBuilder/wxFormBuilder: RAD tool for wxWidgets GUI designThere is a URL listed in the homepage: Last successful Windows build of the master branch, which direct to the file:
https://ci.appveyor.com/api/projects/jhasse/wxformbuilder-461d5/artifacts/wxFormBuilder_win32.zip?branch=master
Which I think is make by the build bot, and just download it, and it contains many dlls like "libwinpthread-1.dll" and "wxmsw30u_aui_gcc_custom.dll", which means the build bot may support MinGW or MinGW-w64 based compiler to build the project.
Any idea?