AttributeError: 'SessionManager' object has no attribute 'run_list'

checkbox-ng is living up to the traditions of it's namesake :D

So in the process of trying the latest packages after some fixes were in place for other bugs, I discovered the following traceback once I tried running tests:

Do you want to resume the previous session? [y, n] n

Executable 'checkbox' invoked with Namespace(c3_url='https://certification.canonical.com/submissions/submit/', check_config=False, command=<checkbox_ng.commands.certification.CertificationCommand object at 0x7f745f6d8240>, debug_console=False, debug_interrupt=False, exclude_pattern_list=[], include_pattern_list=[], log_level=None, not_interactive=False, pdb=False, providers=None, secure_id=None, trace=[], whitelist=[]) has crashed
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/plainbox/impl/clitools.py", line 513, in dispatch_and_catch_exceptions
    return self.dispatch_command(ns)
  File "/usr/lib/python3/dist-packages/plainbox/impl/clitools.py", line 509, in dispatch_command
    return ns.command.invoked(ns)
  File "/usr/lib/python3/dist-packages/checkbox_ng/commands/certification.py", line 142, in invoked
    self.settings, ns).run()
  File "/usr/lib/python3/dist-packages/checkbox_ng/commands/cli.py", line 354, in run
    manager, [job for job in manager.run_list
AttributeError: 'SessionManager' object has no attribute 'run_list'
Traceback (most recent call last):
  File "/usr/bin/canonical-certification-server", line 9, in <module>
    load_entry_point('checkbox-ng==0.4.dev', 'console_scripts', 'canonical-certification-server')()
  File "/usr/lib/python3/dist-packages/checkbox_ng/main.py", line 198, in cert_server
    CertificationNGTool().main(['certification-server'] + args))
  File "/usr/lib/python3/dist-packages/plainbox/impl/clitools.py", line 291, in main
    return self.dispatch_and_catch_exceptions(ns)
  File "/usr/lib/python3/dist-packages/plainbox/impl/clitools.py", line 513, in dispatch_and_catch_exceptions
    return self.dispatch_command(ns)
  File "/usr/lib/python3/dist-packages/plainbox/impl/clitools.py", line 509, in dispatch_command
    return ns.command.invoked(ns)
  File "/usr/lib/python3/dist-packages/checkbox_ng/commands/certification.py", line 142, in invoked
    self.settings, ns).run()
  File "/usr/lib/python3/dist-packages/checkbox_ng/commands/cli.py", line 354, in run
    manager, [job for job in manager.run_list
AttributeError: 'SessionManager' object has no attribute 'run_list'

ii checkbox-ng 0.4~dev+bzr2996+pkg7~ubuntu14.04.1 all PlainBox based test runner
ii plainbox-provider-checkbox 0.5~dev+bzr2996+pkg4~ubuntu14.04.1 amd64 CheckBox provider for PlainBox
ii python3-checkbox-ng 0.4~dev+bzr2996+pkg7~ubuntu14.04.1 all PlainBox based test runner (Python 3 library)
ii python3-checkbox-support 0.3~dev+bzr2996+pkg2~ubuntu14.04.1 all collection of Python modules used by PlainBox providers
ii plainbox-provider-certification-server 0.1~dev+bzr2996+pkg14~ubuntu14.04.1 all Server Certification
ii plainbox-provider-checkbox 0.5~dev+bzr2996+pkg4~ubuntu14.04.1 amd64 CheckBox provider for PlainBox
ii plainbox-provider-resource-generic 0.4~dev+bzr2996+pkg5~ubuntu14.04.1 amd64 CheckBox generic resource jobs provider
ii plainbox-secure-policy 0.6~dev+bzr2996+pkg3~ubuntu14.04.1 all policykit policy required to use plainbox (secure version)
ii python3-plainbox 0.6~dev+bzr2996+pkg3~ubuntu14.04.1 all toolkit for software and hardware testing (python3