Comment 10 for bug 1552985

Today I tried the Xubuntu Xenial daily image and again (live usb), the system was not able to shut down.
In the live session, selected the Xubuntu menu, shut down, when Xubuntu image appeared pressed [F1] to be able to see system messages, I got these messages at the end:

[OK] Stopped target Local File System.
         Unmounting /run/user/999...
         Unmounting cdrom.mount...
         Unmounting /rofs...
         Unmounting /sys/kernel/debug/tracing...
         Unmounting /tmp...
[FAILED] Failed unmounting cdrom.mount.
cdrom.mount
[OK] Unmounted /sys/kernel/debug/tracing.
[OK] Unmounted /run/user/999.
[OK] Unmounted /rofs.
[OK] Unmounted /tmp.
[OK] Reached target Unmount All Filesystems.
[OK] Stopped target Local File Systems (Pre).
[OK] Stopped Create Static Device Nodes in /dev.
[OK] Stopped Remount Root and Kernel File Systems.
[OK] Reached target Shutdown.
[202.959599] reboot: Power down

And the system hangs there, it does not complete the shut down. It does not respond to any keypress, I have to keep the power button pressed to get the computer shut down.