Re: RFC: Adding BBDB to Emacs core

[phillip.lord@russet.org.uk (Phillip Lord)]

Stefan Monnier <monnier@IRO.UMontreal.CA> writes:

>> If I have a package on master in ELPA, and I want to main one version
>> for Emacs-26 and another for Emacs-27,
>
> I would take this as a sign that the package shouldn't be in elpa.git.
>
> elpa.git is for packages which are not specific to a particular Emacs version.


I think that this is wrong and I will give you a use case.

Imagine, for example, that I have a package which I add to ELPA when
Emacs-26 comes out. I maintain this package and expand it slowly. Then,
when Emacs-27 comes out, for example something significant has happened
(say, just for argument sake, the advice system got re-written --
unlikely, but it could happen).

As a package author, I have two choices here: either I move to Emacs-27
and ditch Emacs-26 support. Or I have to put runtime conditional logic
which supports both. I think package authors should have the choice of
freezing the Emacs-26 version of their package when Emacs-27 comes out.

This situation would get worse if we have an "unstable" version of
ELPA. I bet that there is some package already that depends on Emacs-27
at the bleeding edge.

Phil