It seems that one can't build both PX4 and Qgroundcontrol with Qt Creator on one Mac due to different version requirements. While Qgroundcontrol needs XCode 7.3.1 and not newer:
OSX: OSX 10.7 or higher, 64 bit, clang compiler (IMPORTANT: XCode 8 not supported due to Qt bug. Currently only workaround is to use XCode 7.3.1)
PX4 Qt build asks XCode 8
$ cmake .. -G "CodeBlocks - Unix Makefiles"
-- CMAKE_INSTALL_PREFIX: /usr
-- cmake module path: /Users/sagaris/dev/px4/Firmware/cmake
CMake Error at cmake/posix/px4_impl_posix.cmake:192 (message):
PX4 Firmware requires XCode 8 or newer on Mac OS. Version installed on
this system: 184.108.40.20630031
Call Stack (most recent call first):
-- Configuring incomplete, errors occurred!
See also "/Users/sagaris/dev/px4/Firmware/build_creator/CMakeFiles/CMakeOutput.log".
So is there any workaround to use one Mac with Qt for both project development?