A portable version exists, if you are not happy with it and want to discuss that, make a new topic or continue on another existing topic about that please since it’s too separate from the main topic here: compiler compatibility with C++ standards
It might just be my information that is outdated, but I vaguely recalled this: Supporting Qt 6 - What's needed? - #135 by wmayer
and besides that it seems gcc doesn’t work, only clang, I don’t think that’s a big issue though: https://devtalk.freecad.org/t/dll-definition-error-building-on-win10mingw/59007/4