I am confused: you said this is under CentOS 7, so does your Raspberry Pi run CentOS 7, or are you compiling the code under a desktop CentOS 7? I would assume your RPi runs CentOS 7, because you are using ‘./build.sh ospi’. If you are building it on a desktop Linux, you should be ‘./build.sh demo’. I have no experience with CentOS 7, so unfortunately I can’t tell what’s the issue. Sounds like you just need to add a include header in one of those .cpp files. The code has been compiled on Raspbian and also Linux Mint and I did not observe any such error. Make sure you are on master branch. Do a clean git clone to make sure you didn’t modify anything.