https://forum.obarun.org/viewtopic.php?id=1377
You can build it yourself from the PKGBUILD listed in the thread or you can go to arch pkg archive and install the previous edition that didn't need systemd-libs if you don't already have the previous version installed.
If you have at-spi2-core 2.38
then upgrade by ignoring it
# pacman -Su --ignore at-spi2-core
Otherwise wait for Eric to build the pkg and place it in obextra which will satisfy dependencies. Gtk3 depends on this, so any/most desktop applications indirectly depend on this too.