Comment 2 for bug 1741223

glanceclient has the same problem:

$ openstack image save 67fba704-a2f2-4cb4-a681-f12ff7674b74
Traceback (most recent call last): │····················
  File "/usr/lib/python2.7/site-packages/osc_lib/shell.py", line 134, in run │····················
    ret_val = super(OpenStackShell, self).run(argv) │····················
  File "/usr/lib/python2.7/site-packages/cliff/app.py", line 279, in run │····················
    result = self.run_subcommand(remainder) │····················
  File "/usr/lib/python2.7/site-packages/osc_lib/shell.py", line 169, in run_subcommand │····················
    ret_value = super(OpenStackShell, self).run_subcommand(argv) │····················
  File "/usr/lib/python2.7/site-packages/cliff/app.py", line 400, in run_subcommand │····················
    result = cmd.run(parsed_args) │····················
  File "/usr/lib/python2.7/site-packages/osc_lib/command/command.py", line 41, in run │····················
    return super(Command, self).run(parsed_args) │····················
  File "/usr/lib/python2.7/site-packages/cliff/command.py", line 137, in run │····················
    return_code = self.take_action(parsed_args) or 0 │····················
  File "/usr/lib/python2.7/site-packages/openstackclient/image/v2/image.py", line 652, in take_action │····················
    gc_utils.save_image(data, parsed_args.file) │····················
  File "/usr/lib/python2.7/site-packages/glanceclient/common/utils.py", line 286, in save_image │····················
    for chunk in data: │····················
TypeError: 'NoneType' object is not iterable