Ship all the modules for python 3 as well as python 2, ready to switch

Move the python consumers (eg mercurial) across to python 3

Make python 3 the default

Deprecate and remove python 2

It's been over a decade since python 3 came out, and a lot of the world is still using python 2.But we're at the point now where the world has said, and it's time to finally get the 2-to-3 transition over with.And while Tribblix is all about retro styling, it's also all about keeping up. So I put together a plan for migrating Tribblix from python 2 to python 3.This is made a little easier by the fact that there's nothing in Tribblix itself that uses python directly - I haven't made the mistake of having my packaging system or anything like that written in python, for example.There was a little wrinkle in all this. I had got this planned out, and then python 3.7 was just around the corner. So I ended up waiting a little, and put a python 3.6 to 3.7 transition at the beginning of the list.So where am I right now? I've now got all the modules built and packaged for python 3.7, and python 3.6 has been removed from Tribblix. This was made somewhat easier by the fact that no packages in Tribblix yet depended on python 3 - the transition hadn't been started properly, so I could simply throw away all the python 3.6 stuff.As an aside, this had the odd side effect that all the python 3.7 modules were packaged straight away for SPARC, whereas python 3.6 was never finished there - the 3.6 to 3.7 switch was all scripted, rather than manual, so was very little actual work. There were a couple of modules that needed to be updated anyway to work with 3.7 (pyyaml for example), and I took the opportunity to do a bunch of routine module updates at the same time.So just having all the modules turned out to be nearly trivial. Now there's going to be a longer slog migrating all the python consumers across and making python 3 the default. (It might be easiest to make python 3 the default first, so that when building the consumers they automatically pick up the python I want.)I was originally thinking of a fairly slow and structured approach where each step would be a point release of 3.7. But I'm well ahead of that already, and the remaining steps are likely to occur fairly promptly. (Or, as promptly as I have time to do the work.)So it won't be long before we bid farewell to python 2 in Tribblix.