After having problem with adwaita-icon-them-3.24.0, (reported in other bug)
 I decided to give a try by removing gnome service from the
list of "meta-package" to install.

So in fact keeping 'only' XFCE.

I tried two times, once after the adwaita problem, the other after a reboot and from scratch (except partitioning).

The result was the same (from poorly taken notes):
warning: collision encountered: /gnu/store/7qnfb279...hicolor/icon-theme.cache
warning: arbitrarily choosing 7qnfb...icons/hicolor/icons-theme.cache
In Ice-0/boot-9.scm
In unknown file

That's it, what I had noted.

So, I had to boot with an other system to report this, was unable to get guix-sd 0.13.0 usb install 32b to install.