The Python 2 packages set is no longer built by Hydra, and the Python 3.9 set will now be built.
The Python 2 packages set will remain available, however, it will not be built by Hydra or ofBorg. While some have expressed their desire to have a Python2 set around, there has hardly been any effort to keep it working.
Not building Python 2 allows us to build an additional Python 3 set (currently Python 3.9), which is important since Python switched to a yearly release cadence.
Note 2.7 as well as the upstream supported 3.6 through 3.9 are available on master [2]. Versions 3.7, 3.8 and 3.9 will now be built by Hydra. I think we may drop building 3.7 for 21.03 though, to reduce the maintenance burden.