For now, Homebrew document says:
If a library supports both Python 2.x and Python 3.x, the :python dependency should be :recommended (i.e. built by default) and the :python3 dependency should be :optional.
It means when I want to install applications with Python 3 support, (e.g.
brew install vim --with-python3), I can't install it from bottle.
But Python 2 is legacy. It will be EOL in 2020.
Python 3 is recommended unless there is specific reason to need Python 2.
And "building from source" increase CO2 emissions. I want to use bottle as possible.
In macOS 10.13 High Sierra (beta), Ruby, PHP version are updated, but Python is still 2.7.10, same to El Capitan. (ref)
It seems Apple stopped updating Python.
Is there any appropriate reason to keep current "Python 2 as default" policy?
When can we make :python3 as :recommended and :python as :optinal?