The build script is found at the root of the IoTivity repository. Please see here: <IOTIVITY>/auto_build.sh
To see how Jenkins calls this script (and to see partial build system configuration) see this publicly viewable page: https://build.iotivity.org/ci/job/Verify-IoTivity-Scons/configure
To gain access to the above Jenkins page and/or to gain more insight into how the build machine is actually configured, please contact Aric Gardner from Linux Foundation. I have found the best way to start a work item is to draft an email (which is then converted to a ticket on LF’s side) and send it to 'firstname.lastname@example.org'. Aric Gardner is usually the person to pick these items up. If there is more prep work on your side to do, he is pretty good at letting you know what is able to do and what you should do before he can actually take action.
In addition to Aric, you may contact me (Joey Morrow email@example.com) and I will either help you or point in the direction you can find more help.