Some parts referenced from https://www.downtowndougbrown.com/2023/08/how-to-create-a-qt-5-arm-intel-universal-binary-for-mac/
I will be working on a Mac Studio M2 with macOS 14.5. But these instructions should work on any Mac with macOS 12.0 or later. I will also be downloading and building in $HOME/qt but feel free to change VESCBUILDBASE to another folder you with to use.
The resulting build will be in /opt/external/qt-5.15.14 so change the -prefix option if you wish to change that. Also feel free to change -j8 to a higher number if you have more cores available to speed up the build.
Open up Terminal and let's get started!