Commonly needed Python modules, used by Python software developed at OSRF.
If you are releasing (using stdeb or on the ROS buildfarm) for any Ubuntu < focal, or for any OS that doesn't have a key for python3-importlib-metadata, then you need to use the 1.0.x branch, or the latest 1.<something> branch, because starting with 2.0.0, that dependency will be required.
If you are using Python 2, then you should use the python2 branch.