There is another problem related to Jupyter.
Up to (and including) ROOT 6.34, you define “JUPYTER_CONFIG_DIR”, but you do not care about “JUPYTER_CONFIG_PATH” (which may come from a newer ROOT version).
From ROOT 6.36, you define “JUPYTER_CONFIG_PATH”, but you do not care about “JUPYTER_CONFIG_DIR” (which may come from an older ROOT version).
This creates a problem when one switches between versions, e.g.:
source /.../root_v6.34.10/bin/thisroot.sh
source /.../root_v6.36.06/bin/thisroot.sh
One then has:
JUPYTER_CONFIG_DIR="/.../root_v6.34.10/etc/notebook"
JUPYTER_CONFIG_PATH="/.../root_v6.36.06/etc/notebook"
It seems to me that you should fix it in ROOT 6.34+, so that, even if you do not define some variable, it should try to “drop_from_path” any possible “old_rootsys” entries from another version (older or newer).