[portgroups] Python

[Mojca Miklavec]

On Fri, 13 Sep 2019 at 03:51, Bjarne D Mathiesen wrote:
>
> Richard L. Hamilton wrote:
> > Depending on the results, with some effort, it might be possible to drop some of the intermediate versions. But only if a later suitable (for everything dependent on it) version is possible on every supported OS. And it would mean bumping portfiles, and rebuilding everything depending on dropped versions.  It probably wouldn't be worth the bother, and given all the constraints, might only get rid of a few versions.
> >
>
> so we've got 2 issues here :
>     - which pythonXY the pyXY-{name} support
>       and whether theese can be brought up to python37
>     - whether any Portfile that demands a pythonXY that isn't python37
>       can be updated to depend on python37 instead
>
> We'll need some statistict / overview on this matter.
> I'll look into this.
>
> It's also a question about keeping the macports infrastructure up-to-date.
>
> I've eg somehow gotten libsvm installed, and it has :
>     Variants:  [+]java, [+]python27, python34, [+]tools, universal
> as well as being seriously out-of-date:
>     libsvm @3.20_2 -> Version 3.24, September 2019

This looks like an obvious example of a port that simply no-one
touched for years and should probably be easy to update, replace
python34 with python37 (as well as make that one default if it works
as expected).

In general updating from 2.7 to 3.7 is not always possible, in
particular we still don't have the port for wxWidgets (Phoenix), and
software needs to be rewritten to use that one as well.

I would say that we'll need to keep 2.7 around, but of course switch
to 3.7 as much as possible.

Personally I don't mind if we remove all traces of Python 2.4-2.6
which should be very easy. Almost nothing depends on that, it's just
there if someone would want to some extent still run the older python.

Removing any traces of 3.x up to 3.6 should be straightforward, but
requiring quite a bit of (tedious) work.

Mojca

PS: just removing the numbers from portgroup is not sufficient. All
ports that don't specify the default version need to be revbumped and
checked that they are compatible with python 3.7 at least, or at least
those should specify the default python version.