Good question. @calmh actually tried to build it today for Mac but the build failed: https://gist.github.com/calmh/5ba12fdf06da21edac0d72f76f97081c
I know CMake, C++ and Qt but I have no experience with Mac. Maybe someone with CMake, C++/Qt and Mac experience could help.
I can only suspect that linking the shared library c++utilities against the static library iconv is the problem. Maybe because the static lib does not contain relocatable code which might be required when building the shared lib. So I can just give the recommendation to link statically against all dependencies (tested under Windows) or link everything dynamically (tested under Linux and Windows).
It was also required to disable install targets due to the error
install TARGETS given no BUNDLE DESTINATION for MACOSX_BUNDLE executable. Not sure how this is usually handled under Mac.
Also, the Dolphin integration must be disabled explicitly and the directory cpp-utilities must be renamed to c++utilities when using the 'building this straight' approach. I will fix those issues.