The upgrade to Excalibur on my "hot backup" machine went fine.
Today I did my main desktop. Trying to start X gives me...

=====================================================================
X.Org X Server 1.21.1.16
X Protocol Version 11, Revision 0
Current Operating System: Linux dev2 6.12.101+deb13-amd64 #1 SMP
PREEMPT_DYNAMIC Debian 6.12.101-1 (2026-08-05) x86_64
Kernel command line: BOOT_IMAGE=/boot/vmlinuz-6.12.101+deb13-amd64
root=UUID=7d3e56c6-20b3-489d-ac01-8815d32f055e ro quiet noexec=on
net.ifnames=0 ipv6.disable=1
xorg-server 2:21.1.16-1.3+deb13u3devuan1
(https://www.devuan.org/os/community)
Current version of pixman: 0.44.0
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/home/waltdnes/.local/share/xorg/Xorg.0.log", Time: Thu
Aug 13 10:04:21 2026
(==) Using config directory: "/etc/X11/xorg.conf.d"
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(EE) [libseat/backend/seatd.c:66] Could not connect to socket
/run/seatd.sock: Permission denied
(II) [libseat/libseat.c:76] Backend 'seatd' failed to open seat,
skipping
(EE) Server terminated with error (1). Closing log
file.local/share/xorg/Xorg.0.log" for additional information.
xinit: giving up
xinit: unable to connect to X server: Bad file descriptor
xinit: server error
=====================================================================

I'm file-attaching the gzipped Xorg.0.log file for further diagnostics.
For now I'll run off my "hot backup".

--
Walter Dnes <waltdnes@???>
There are 2 types of people in this world
1) Those who can extrapolate from incomplete data