ImportError: cannot import name EnvError

Mojo 0.2.5-10, when backed by juju-deployer 0.6.4, is failing us like so:

00:14:27.245 2016-09-21 07:33:34 [INFO] Running: python /usr/bin/juju-deployer -c /srv/mojo/mojo-openstack-specs/trusty/osci-mojo/charms/specs/full_stack/next_deploy_baremetal/icehouse/baremetal7.yaml -s 0 -t 4500 -d ${MOJO_SERIES}-icehouse -W -u
00:14:27.876 2016-09-21 07:33:35 [ERROR] Juju Status: environment: maas-trusty
00:14:27.876 machines:
00:14:27.876 "0":
00:14:27.876 agent-state: started
00:14:27.876 agent-version: 1.25.6.1
00:14:27.876 dns-name: fat-machine.dellstack
00:14:27.876 instance-id: /MAAS/api/1.0/nodes/node-d4692494-8228-11e4-8078-d4bed9a84493/
00:14:27.876 series: trusty
00:14:27.876 hardware: arch=amd64 cpu-cores=8 mem=49152M tags=node-d4692494-8228-11e4-8078-d4bed9a84493,demo,uosci
00:14:27.876 availability-zone=default
00:14:27.876 state-server-member-status: has-vote
00:14:27.876 services: {}
00:14:27.876
00:14:27.876 2016-09-21 07:33:35 [ERROR] There was an unrecognised problem with running a deploy phase
00:14:27.876 2016-09-21 07:33:35 [ERROR] Error found during deployment phase
00:14:27.876 Traceback (most recent call last):
00:14:27.876 File "/usr/bin/juju-deployer", line 9, in <module>
00:14:27.876 load_entry_point('juju-deployer==0.6.4', 'console_scripts', 'juju-deployer')()
00:14:27.876 File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 542, in load_entry_point
00:14:27.876 return get_distribution(dist).load_entry_point(group, name)
00:14:27.876 File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2569, in load_entry_point
00:14:27.876 return ep.load()
00:14:27.876 File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2229, in load
00:14:27.876 return self.resolve()
00:14:27.876 File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2235, in resolve
00:14:27.876 module = __import__(self.module_name, fromlist=['__name__'], level=0)
00:14:27.876 File "/usr/lib/python2.7/dist-packages/deployer/cli.py", line 18, in <module>
00:14:27.876 from deployer.env import select_runtime
00:14:27.876 File "/usr/lib/python2.7/dist-packages/deployer/env/__init__.py", line 2, in <module>
00:14:27.876 from .go import GoEnvironment
00:14:27.876 File "/usr/lib/python2.7/dist-packages/deployer/env/go.py", line 9, in <module>
00:14:27.876 from jujuclient import (
00:14:27.876 ImportError: cannot import name EnvError
00:14:27.916 + [[ 1 != \0 ]]
00:14:27.916 + echo ' ! Mojo run manifest failed.'
00:14:27.916 ! Mojo run manifest failed.