Re: switching to Python 3.x

[Han-Wen Nienhuys]

On Sun, Jan 26, 2020 at 3:04 PM Jonas Hahnfeld <address@hidden> wrote:
> > > > So far, I've only received a single (positive) response off-list and a
> > > > bit of feedback on the posted patches. What do others think?
> > > > To make this explicit: The proposal is to drop support for Python 2
> > > > (now EOL), requiring everyone wishing to build LilyPond 'master' to
> > > > have an appropriate version of Python 3 available. This should be
> > > > sufficiently easy (see above), but I'd like to have consensus on this.
> > >
> > > When we switch over GUB, we also need to switch over the 2.20 branch.
> > > It's not just master that is affected.
> >
> > But we only need to switch GUB to py3 when we package 2.21 with GUB.
> > We could kick this problem down the road until we really need a GUB
> > build of 2.21, which may well be a few months in the future, or never
> > if we decide to move to some other packaging mechanism (cf. the
> > discussion of Docker/Windows)
> >
> > I don't think it's reasonable for us to ask Jonas to also package
> > python3 for GUB as a precondition to getting his patches in.
>
> I'm going to start by quoting myself:
> > > > > On the GUB side, I already added a spec for Python 3.7.4 (also for
> > > > > Windows via binary packages) and this worked successfully in 
> > > > > September.
> So even if you don't think it's needed, I already did. Even though I
> would fully support switching away from GUB!
>

Kudos for biting through GUB.

> What David is concerned about (as far as I understand) is that we need
> to modify the spec for LilyPond to require the new python3 package as a
> dependency. This will (obviously) not work for packaging 2.20.

Fair enough, but that would only be a problem if we ever have to
produce a 2.20.1 . We could delay 2.21.0 for a while. If we get lucky,
we never have to produce a 2.20.1. If we do, we might have to backport
the py3 patch.


-- 
Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen