kdepim cmake ftbfs with libcaldav and libcardav options

kdepim 3.5.13 has two cmake build options to support libcaldav and libcarddav: WITH_CALDAV WITH_CARDDAV Both build options are disabled as default. I added the options and installed both the libcaldav and libcarddav packages. I'm using libcaldav_0.6.5-2debian2 and libcarddav_0.6.2-2debian2. kdepim fails to build. The problem is finding libcaldav.h and libcarddav.h, which are installed in /opt/trinity/include/libcaldav-0.6.2 and /opt/trinity/include/libcarddav-0.6.1 respectively. With autotools I would use the --with-extra-includes option. How do I fix this in cmake? Darrell