>> *Theoretically*, this fixes the issue.
>
> I still don't understand how this MR helps.
>
> Say I am running 2.25.0 which has this fix, but I have 2.25.1
> installed globally. It will predictably make 2.25.0 use the font
> files from 2.25.1 because they have a higher version. Or am I
> missing the point?
You are correct. The MR handles the opposite case, i.e., that a newer
LilyPond version uses a newer Emmentaler font.
Given that the `<reset-dir />` element[*] was only introduced in
FontConfig 2.13.91 (released in June 2019, which is too new for
general use), your idea of using two FontConfig setups is probably the
way to go.
Werner
[*] This removes all font directories previously added by `<dir>`.
