Comment 6 for bug 1762205

I am also affected by this - ubuntu 18.04 - but "upgraded"/updated continuously from beta

1) There seems to be packages missing after installing gnome-boxes, these ones were not installed so I installed them AFTER I installed gnome-boxes:
sudo apt-get install qemu qemu-kvm libvirt-bin

2) I can't start the VM and have the same issue as described above. The fix with adding group=kvm and adding me to the kvm group works for me, too!

Maybe there are "some lines missing" in the installation process of gnome-boxes?

It is not only "annoying" it makes the package completely unusable without this fix.