Could you paste here the error you get at teardown?
I don’t know what SetNameTitile does that could cause this, but it looks like it modifies some internal memory management of the cloned tree. Perhaps @moneta can comment.
It happens during teardown in TROOT::CloseFiles(), and it must be related to the internal memory management of the cloned tree.
This is ok:
import ROOT
Tree = ROOT.TTree()
Tree.SetNameTitle("Name", "Name")
A workaround to prevent this is to add ROOT.SetOwnership(Tree, False) to prevent the deletion of the cloned tree from Python, since it seems there might be some double deletion going on.