Thanks for your response. I had followed the steps that you provided in the link and so I was puzzled by that error, which seems to come from numdiff. And so I looked back at the "cmake -C..." step and I see several warning regarding *.h include files not found. Do you by any chance have a list of all dependencies I need to have on my end to be able to compile? I am trying to install on centos7 using cmake 3.16.4 and gcc 7.4.0. Back in 2018 I compiled cmtk 3.3.1 with no problems at all. By the way, is there a container version for cmtk? Thanks again!