[gentoo-project] For next council meeting: moving Portage to python3.6+

[Daniel Robbins]

Hi there,

Zac Medico and I would like to discuss the following at the next council
meeting: moving Portage to support only python3.6+. One of the primary
benefits of this change is that it will allow us to use python's native
async implementation as we look to make Portage faster at a critical time
when we are looking to improve Portage performance. As we approach the
stabilization of python3.6 in Gentoo, it seems like a good time to discuss
the process of jettisoning 2.7 support and standardizing on 3.6 for Portage.

Right now, a custom 'asyncio-like' set of classes is used for async in
Portage. This limits interoperability with other async-friendly python
modules and produces additional maintenance overhead for the project.

Maybe even more importantly, 3.6+ compatibility also gives us the ability
to use many other new language features and reduce the maintenance overhead
of having 2.7 compatibility for the extensive Portage code-base. We expect
that this will improve the velocity of Portage development, provide
opportunities to improve Portage functionality and also allow us clean up a
lot of unnecessarily complex code (and eliminate code) that is there only
to ensure compatibility with 2.7.

Best,

Daniel