From 10.2 (or maybe 10.1) the runtests.py script requires python3. The hashbang line in this script just specifies python. If this resolves to python2, as it does on OpenSuse, the user will be presented with a pythonesque error message, which may be unintelligible to a non-python user. It would be better to check the python version at the top of the script, and present a plain language message.