ImportError: cannot import name sugar

Traceback (most recent call last):
  File "/usr/local/bin/solar", line 6, in <module>
    from solar.cli.main import run
  File "/vagrant/solar/cli/main.py", line 34, in <module>
    from solar.cli.orch import orchestration
  File "/vagrant/solar/cli/orch.py", line 25, in <module>
    from solar.orchestration import filters
  File "/vagrant/solar/orchestration/__init__.py", line 20, in <module>
    from solar.orchestration.executors import Executor
  File "/vagrant/solar/orchestration/executors/__init__.py", line 24, in <module>
    invoke_on_load=False,
  File "/usr/local/lib/python2.7/dist-packages/stevedore/driver.py", line 46, in __init__
    verify_requirements=verify_requirements,
  File "/usr/local/lib/python2.7/dist-packages/stevedore/named.py", line 55, in __init__
    verify_requirements)
  File "/usr/local/lib/python2.7/dist-packages/stevedore/extension.py", line 171, in _load_plugins
    self._on_load_failure_callback(self, ep, err)
  File "/usr/local/lib/python2.7/dist-packages/stevedore/extension.py", line 163, in _load_plugins
    verify_requirements,
  File "/usr/local/lib/python2.7/dist-packages/stevedore/named.py", line 123, in _load_one_plugin
    verify_requirements,
  File "/usr/local/lib/python2.7/dist-packages/stevedore/extension.py", line 186, in _load_one_plugin
    plugin = ep.load(require=verify_requirements)
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2088, in load
    entry = __import__(self.module_name, globals(),globals(), ['__name__'])
  File "/vagrant/solar/orchestration/executors/zerorpc_executor.py", line 31, in <module>
    import zerorpc # NOQA
  File "/usr/local/lib/python2.7/dist-packages/zerorpc/__init__.py", line 29, in <module>
    from .context import *
  File "/usr/local/lib/python2.7/dist-packages/zerorpc/context.py", line 29, in <module>
    import gevent_zmq as zmq
  File "/usr/local/lib/python2.7/dist-packages/zerorpc/gevent_zmq.py", line 28, in <module>
    from zmq import * # noqa
  File "/usr/local/lib/python2.7/dist-packages/zmq/__init__.py", line 54, in <module>
    from zmq import sugar
ImportError: cannot import name sugar