X client from Wayland to X11 through ssh

[Eben King <eben@gmx.us>]

Hi.  I have this machine "alexandria" onto which I installed Debian
yesterday:

eben@alexandria:~$ cat /etc/debian_version
12.10

It has a video card and a keyboard, but to log in there I have to get
down on the floor, so I usually access it via ssh.  Right now I'm trying
to use synaptic to install some software, but I get this when I try as me:

,--
| eben@alexandria:~$ synaptic-pkexec
| ==== AUTHENTICATING FOR com.ubuntu.pkexec.synaptic ====
| Authentication is required to run the Synaptic Package Manager
| Authenticating as: root
| Password:
| polkit-agent-helper-1: error response to PolicyKit daemon:
| GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: No session for
|cookie
| ==== AUTHENTICATION FAILED ====
| Error executing command as another user: Not authorized
|
| This incident has been reported.
| eben@alexandria:~$
'--

As root it's even shorter:

,--
| root@alexandria:~# synaptic
| Failed to initialize GTK.
|
| Probably you're running Synaptic on Wayland with root permission.
| Please restart your session without Wayland, or run Synaptic without
| root permission
| root@alexandria:~#
'--

xev works as not-root, so X clients in general work.  So how do I get
around this?  Installing not-Wayland is an option, but I probably should
replace it with some WIMP interface so if I need it, it's there.  Thanks.