Comment 0 for bug 1386275

$ dpkg-query --show curtin python-curtin util-linux
curtin 0.1.0~bzr190-0ubuntu1
python-curtin 0.1.0~bzr190-0ubuntu1
util-linux 2.25.1-3ubuntu4

$ sudo curtin --showtrace install http://cloud-images.ubuntu.com/utopic/current/utopic-server-cloudimg-amd64-root.tar.gz

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/curtin/commands/main.py", line 96, in main
    sys.exit(args.func(args))
  File "/usr/lib/python2.7/dist-packages/curtin/commands/block_meta.py", line 53, in block_meta
    meta_simple(args)
  File "/usr/lib/python2.7/dist-packages/curtin/commands/block_meta.py", line 150, in meta_simple
    devices = block.get_installable_blockdevs()
  File "/usr/lib/python2.7/dist-packages/curtin/block/__init__.py", line 118, in get_installable_blockdevs
    unused = get_unused_blockdev_info()
  File "/usr/lib/python2.7/dist-packages/curtin/block/__init__.py", line 81, in get_unused_blockdev_info
    bdinfo = _lsblock(['--nodeps'])
  File "/usr/lib/python2.7/dist-packages/curtin/block/__init__.py", line 70, in _lsblock
    (out, _err) = util.subp(basecmd + list(args), capture=True)
  File "/usr/lib/python2.7/dist-packages/curtin/util.py", line 67, in subp
    cmd=args)
ProcessExecutionError: Unexpected error while running command.
Command: ['lsblk', '--noheadings', '--bytes', '--pairs', '--out=ALIGNMENT,DISC-ALN,DISC-GRAN,DISC-MAX,DISC-ZERO,FSTYPE,GROUP,KNAME,LABEL,LOG-SEC,MAJ:MIN,MIN-IO,MODE,MODEL,MOUNTPOINT,NAME,OPT-IO,OWNER,PHY-SEC,RM,RO,ROTA,RQ-SIZE,SIZE,STATE,TYPE,UUID', '--nodeps']
Exit code: 1
...
is ambiguous; possibilities: \'--output\' \'--output-all\'\n\nUsage:\n lsblk [options] [<device> ...]\n\nOptions:\n -a, --all

basically, util-linux's lsblk gained a '--output-all' argument, which made our use of '--out' ambiguous. Note, back to 12.04 supports --output per http://manpages.ubuntu.com/manpages/precise/en/man8/lsblk.8.html .
not sure why I used '--out'.