Kai Haberzettl <khaberz(a)synnet.de> writes in xemacs-beta(a)xemacs.org:
 SL Baur <steve(a)xemacs.org> writes:
> It builds for me but fails to run dropping core deep in the bytecode
> interpreter.  Don't throw away your only working XEmacs 21 if you're
> attempting to upgrade. 
 No problems here (yet).
 libc-5.4.46-1
 gcc-2.7.2.1-6 
Thanks for the report.  Note that the changes aren't fully committed
yet.
Try this:
xemacs-21.2.5 -nw -q
C-x C-f ~/.emacs
M-x font-lock-mode
M-x fast-lock-mode