sudo nova-rootwrap /etc/nova/rootwrap.conf privsep-helper --config-file /usr/share/nova/nova-dist.conf

Traceback (most recent call last):
  File "/bin/privsep-helper", line 10, in <module>
    sys.exit(helper_main())
  File "/usr/lib/python2.7/site-packages/oslo_privsep/daemon.py", line 526, in helper_main
    cfg.CONF(args=sys.argv[1:], project='privsep')
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2141, in __call__
    self._check_required_opts()
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2879, in _check_required_opts
    raise RequiredOptError(opt.name, group)
oslo_config.cfg.RequiredOptError: value required for option privsep_sock_path in group [DEFAULT]