Re: [RFC] Transition to Guile 3.0

[Han-Wen Nienhuys]

On Sun, Nov 5, 2023 at 10:36 PM Jonas Hahnfeld via Discussions on LilyPond
development <lilypond-devel@gnu.org> wrote:

> Hi all,
>
> I hear LilyPond hasn't changed its Guile version since some time (more
> than 18 months). So before we get too comfortable with the current
> situation, let me propose to move to Guile 3.0. Below is a plan for
> that switch, with a transition period to test the official binaries.
> Last time, when going from Guile 1.8 to version 2.2, the switch had to
> coincide with moving away from GUB. Between Guile 2.2 and 3.0, we could
> in principle support both versions for a longer period. However, I
> personally think that a full transition and dropping support for Guile
> 2.2 is the more reasonable approach: It will reduce testing
> configurations (both for development and user reports) and hopefully
> enable some future cleanups in the code.
>

Could you say a bit more about the benefits/disadvantages for the user? I
had the impression that Guile 3 had different (worse?) performance
characteristics relative to 2.2, but it's been a while.

IIRC, one of the arguments to drop 1.8 is that Guile pre-2.x did not
support installing multiple versions alongside each other, which forced
distributions to choose whether to ship LilyPond or a recent version of
Guile. With 2.2 and later, that dilemma disappeared.

I quickly grepped over the source (grepping for SCM_MAJOR_VERSION), but the
bifurcations look very modest.


-- 
Han-Wen Nienhuys - hanwenn@gmail.com - http://www.xs4all.nl/~hanwen