I installed with 64b.
The collision happened in 64b, but did not stop installation.
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
I have taken pencil notes which was probably a bit broken.
I have tried to install guix sd 0.13.0 32 bit on usb key.
It broke at some file, at 78% (12.8 MiB file):
https://mirror.hydra.gnu.org/guix/nar/gzip/qs27jxbxjpvw5bv49nzw9r91hj00r12j-adaita.icon-theme-3.24.0
well that's what I have noted