A priori I don’t see thisroot.sh changing system path in LD_LIBRARY_PATH, only adding $ROOTSYS/lib, which is innocuous. For Python, adding $ROOTSYS/lib to PYTHONPATH would be undesirable when running anaconda, but that’s a simple matter of disabling cmake build python if a setup.py were provided and used.
Either way, what I read in this topic is folks having problem getting the right python picked up by cmake, which all happens before sourcing thisroot.sh.
Providing a setup.py is trivial, as described above, and will allow folks to deal with all the pythons they care to carry on their system in a systematic way. And again, since it’s so simple, all the time spent discussing it has taken more than the coding time would have been, so I’ve said my say am an done with it.