bug#58474: 29.0.50; gnus does not startup in latest master: (void-variable gnus-local-domain)

[Eli Zaretskii]

> From: Uwe Brauer <oub@mat.ucm.es>
> Cc: Uwe Brauer <oub@mat.ucm.es>, 58474@debbugs.gnu.org
> Date: Wed, 12 Oct 2022 22:22:21 +0200
> 
> > Did you try looking up this variable in NEWS?
> 
> 
> Sigh, I did now, 
> ** Some functions and variables obsolete since Emacs 24 have been removed:
> 
> But no hint how to somehow use it anyhow.

Look at the code which caused the problem:

> Debugger entered--Lisp error: (void-variable gnus-local-domain)
>   (or gnus-local-domain (message-make-domain) (system-name) "")
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

So if gnus-local-domain is nil, the code in bbdb already knows how to
deal with that, it just needs the variable to exist.

Now look at how this obsolete variable was defined in Emacs 28:

 (defcustom gnus-local-domain nil

This is how you have been "using" this variable since Emacs 24: with a
nil value.  So just

  (defvar gnus-local-domain nil)

somewhere in your init file should do.  Better yet, modify bbdb to
remove all the references to that variable.