The following message is a courtesy copy of an article
that has been posted to comp.emacs.xemacs as well.
Graham Borland <graham(a)picsel.com> writes:
> I'm using XEmacs 21.1.14 and Ediff 2.76.1. Ediff doesn't work any
> more; invoking it via Pcl-CVS causes the frame to split into two
> windows, as expected, but I get a beep and the little Ediff control
> window (frame?) doesn't pop up like it used to. I get an error about
> a variable "top-gutter".
> I suspect that this version of Ediff isn't compatible with Xemacs
> 21.1.14. If that's the case, then why didn't XEmacs spot this when I
> upgraded my packages using the automatic package management tools?
> It seems a bit silly that it detected the upgrade, but didn't notice
> that it wouldn't actually work with itself.
> How do I make it work? I will not upgrade to XEmacs 21.4.* until the
> font bugs have been fixed. (Some of my fonts were still appearing
> far too large when I tried 21.4.6 a couple of weeks ago.)
It looks like you're right - ediff now expects gutter support.
Unfortunately, the package system does not have a sophisticated
requirements capability built in.
I or someone else on the xemacs-beta list will have a look at this
soon, but for the time being, you can workaround the problem by not
using a separate frame for the ediff-control buffer:
(setq ediff-window-setup-function 'ediff-setup-windows-plain)