Trying to emerge all tools for qemu/kvm, stuck at trying to emerge virt-manager.

After setting my useflags with the following command:
echo 'app-emulation/virt-manager gtk policykit' >> /etc/portage/package.use
portage spits out the following:

localhost /home/svenm # emerge -av app-emulation/virt-manager

These are the packages that would be merged, in order:

Calculating dependencies... done!

emerge: there are no ebuilds to satisfy "dev-python/argcomplete[python_targets_python3_9(-)]".
(dependency required by "app-emulation/virt-manager-4.1.0::core-kit[python_single_target_python3_9,-test]" [ebuild])
(dependency required by "app-emulation/virt-manager" [argument])