I submitted the KG-UV9D Plus driver a few years back. At that time I warned that Fedora Linux and others were deprecating Python 2.7. This has been a self inflicted cliff that the Python community has been looking at for well over 10 years as I warned back then. That means that at some point whatever 2.x people are using will no longer work and no one will look at the issues. So this is not news.

I don't know what the lead developers are planning/thinking but I have heard rumors that a packaging (flatpak/appimage/snap) that included the 2.7 suite would do just fine. Well, it won't. Something outside that sandbox will change. Microsoft can do it anytime. Apple does it all the time. Linux no longer cares.

I know the GUI change is painful. Neither GUI option Python offers warms my heart but I do know that what is running now for CHIRP is dead.

I have been down this road many times over the decades since I first started in Open Source (long before python even existed) and it is clear that either the project get serious about the work, is visible to the community about its work, or it dies. It will join Common Desktop, Algol, and Netscape in the dustbin. There is a lot of python 2 code that is just dead because the maintainers simply did nothing.

If the current maintainers are not responsive, I suggest a group just fork the project and get on with it. And I second the motion on moving from Hg to git.

p.s. I fairness to the author, this is a hard choice. Python has never been on my list of ecosystems that I'd spend a lot of time in. The Python community has made more that a few stumbles and blunders since the beginning. All I have ever been able to say for it was that it was better than Perl... And the 2->3 fiasco has been a bumble that has made whole communities move to GO or other technologies with less penchant for seeking out potholes to fall into. I have only written new code/apps for demo or reference implementations, e.g. DBus clients.

Good luck.