Hmm, I have one 64bit Linux VM that has everything needed to generate binaries for Linux and Windows in both 64bit and 32bit. And Armhf. And so, at testing and release time, one script to package all except the MacOS.
I have described it all on the cross compiling wiki page and, from time to time, rebuild it all using those instructions. So, if you have problems, I would be keen to work through them with you so to improve the documentation.
Once setup, its a delight to use.
Davo