The cleanup on exception was commented out. If there isn't a reason for that then the attached patch runs cleanup on BaseException (to catch interrupts) and after post_install, which removes the iso mount.
** Patch added: "Cleanup after interrupt, exception and at end." https://bugs.launchpad.net/ubuntu/+source/vm-builder/+bug/685258/+attachment/1755582/+files/cleanup_properly.patch -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to vm-builder in ubuntu. https://bugs.launchpad.net/bugs/685258 Title: vmbuilder fails to unmount cdrom cleanly -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs