Traceback (most recent call last):
  File "/usr/bin/ubuntu-vm-builder", line 29, in <module>
    VMBuilder.run()
  File "/usr/lib/python2.6/dist-packages/VMBuilder/__init__.py", line 66, in run
    frontend.run()
  File "/usr/lib/python2.6/dist-packages/VMBuilder/plugins/cli/__init__.py", line 67, in run
    vm.create()
  File "/usr/lib/python2.6/dist-packages/VMBuilder/vm.py", line 469, in create
    raise e
VMBuilderException: Process (['kpartx', '-d', '/tmp/vmbuilderuXfJYm/disk0.img']) returned 1. stdout: , stderr: device-mapper: remove ioctl failed: Device or resource busy
ioctl: LOOP_CLR_FD: Device or resource busy