Found something else c++ related:
KSDK_1.1.0/platform/system/inc/fsl_clock_manager.h:480:54: error: parameter 'callbacksPtr' includes pointer to array of unknown bound 'clock_manager_callback_user_config_t* [] {aka ClockManagerCallbackUserConfig* []}'
uint8_t callbacksNumber);
If you include fsl_clock_manager in a cpp file you get this error. C++ doesn't like the array syntax in the function call without a size bound.