Re: Python 3, was Re: ANN: Frescobaldi 2.19.0

[David Kastrup]

Andrew Bernard <address@hidden> writes:

> Hi David,
>
> But lilypond ships its own internal version of python in
> …lilypond/usr/bin.

Assuming that you install from our precompiled binary packages.
Obviously, that's not what the developers do since they need to run
LilyPond right after compiling it.  Also obviously that is not what the
packagers of distributions do since they compile a native version of
LilyPond and most certainly do not ship versions of Python crosscompiled
by us.

> I am aware the entire ecosystem has to be ported. I am offering to do
> the work.

Check out working on and with GUB for compiling various binaries first
in order to figure out how much work that's actually going to be.
That's a rather big hurdle, and it does not help overly with GNU/Linux
systems (and MacPorts and whatever else) packaging their own
compilations.  But the GUB hurdle of course is our personal showstopper.

> But I don’t understand why the system vesion of python matters. Why do
> we bundle it then?

We only bundle it for our installers, but LilyPond is obviously also
compilable natively.

> Also, python 2 and 3 stand happily side by side on my openSUSE
> systems, ny Ubuntu systems, my Fedora systems, and my Debian
> systems.

But they don't magically don't turn #!/usr/bin/python (or whatever else)
into #!/usr/bin/python3 and the latter will stop working with Python 4
anyway.

> I am having trouble seeing what the issue is. If there comes a
> dependcy on python 3, surely anybody who is capable of downloading and
> installing lilypond can also download and install python 3?

The "surely anybody who is capable of downloading and installing
LilyPond can also ..." argument is nonsense.  We are not trying to prove
mathematically that it is possible to install LilyPond, we are talking
about the kind of practical hurdle imposed here.

If you want to talk about theories, one could compile LilyPond natively
under Windows.  That's what Git also does, requiring the attention of
something like two developers and trailing half a year behind.
LilyPond's Windows version just falls out of our release process,
simultaneously with the rest.

Everything requiring constant effort and attention, even if you think
it's not a big deal, is something that is keeping people from using
LilyPond, or keeping developers from working on more important things.

Upgrading to a newer version of GCC stopped our release process from
working for several months.  That's exactly the kind of "it should not
be a big deal" that you are talking about here.

-- 
David Kastrup