guile-g-golf installation prevents Ubuntu login

[Mortimer Cladwell]

Ubuntu 23.10
guile-g-golf 0.8.0-a.1

Hi,
I guix package -i guile-g-golf then from the examples directory try:

guix shell --pure --no-grafts guile guile-g-golf gtk@4 -- ./hello-world.scm

Compiles without errors but nothing happens - no error messages, no gui.

Furthermore I shut down for the day, next day I can't login to Ubuntu. I
enter login password, screen freezes for about a minute then returns me to
the login prompt. I go to a terminal, futz around for a couple of days and
end up doing a full reinstall of Ubuntu as I did not make the connection
with the installation of g-golf (through guix).

Second time I make the connection, uninstall g-golf at a terminal - can
login.
It's repeatable - install g-golf - can't login, uninstall can login.

Anyone know what is going on?
Thanks
Mortimer