option('lib_install_dir',type:'string',value:'',description:'Override install dir for the shared library (used by the fourdst umbrella to place libs inside the Python package in wheel builds). Empty = default libdir.')
option('header_install_dir',type:'string',value:'',description:'Override the header install root (used by the fourdst umbrella to place headers inside the Python package in wheel builds). Empty = default includedir.')