In virt-manager some operations (e.g. creating storage as in the default qcow format) require qemu-img, it would be great if it could use package-kit to enable this from inside the app itself.
Thanks for the suggestion. We previously had packagekit integration in virt-manager but it turned out to be a total pain to maintain over the long term and was removed in v2.0.0, so this won't be implemented. You should file a bug with your distro suggesting that virt-manager or libvirt have appropriate deps on the package that provides qemu-img