I've run into this --or something similar-- too. $ autopkgtest-buildvm-ubuntu-cloud -v
When you run this on an Ubuntu 17.04 (zesty) host, it finishes quickly and leaves you with a nice autopkgtest-zesty-amd64.img. When you run the same command on an Ubuntu 16.10 (yakkety) host, it hangs and eventually times out. I've seen it hang in different spots, so I'm not sure what's going on, but usually when it times out, it does indicate a timeout in cloud-init. E.g. [ 60.843487] cloud-init[1416]: Found kernel: /boot/vmlinuz-4.9.0-11-generic --> hangs here for a long time, but eventually returns Starting Cleanup of Temporary Directories... [ OK ] Started Cleanup of Temporary Directories. --> hangs here for a long time timed out on cloud-init qemu-system-x86_64: terminating on signal 15 from pid 6948