exceptions.AttributeError: 'UnitAgent' object has no attribute 'lifecycle'

I was analyzing why my juju cluster was down. The particular instance I was analyzing had the jenkins-slave charm deployed.

Reading /var/lib/juju/units/jenkins-slave-*/charm.log I found the following unhandled exception:

2012-11-13 09:04:23,261: twisted@ERROR: Unhandled error in Deferred:
2012-11-13 09:04:23,262: twisted@ERROR: Unhandled Error
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1181, in unwindGenerator
    return _inlineCallbacks(None, gen, Deferred())
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1039, in _inlineCallbacks
    result = g.send(result)
  File "/usr/lib/python2.7/dist-packages/juju/agents/base.py", line 250, in stopService
    yield self.stop()
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1181, in unwindGenerator
    return _inlineCallbacks(None, gen, Deferred())
--- <exception caught here> ---
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1039, in _inlineCallbacks
    result = g.send(result)
  File "/usr/lib/python2.7/dist-packages/juju/agents/unit.py", line 127, in stop
    if self.lifecycle.running:
exceptions.AttributeError: 'UnitAgent' object has no attribute 'lifecycle'

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: juju 0.5+bzr531-0ubuntu1.3
ProcVersionSignature: User Name 3.2.0-32.51-virtual 3.2.30
Uname: Linux 3.2.0-32-virtual x86_64
ApportVersion: 2.0.1-0ubuntu14
Architecture: amd64
Date: Tue Nov 13 09:23:43 2012
Ec2AMI: ami-000000bf
Ec2AMIManifest: FIXME
Ec2AvailabilityZone: nova
Ec2InstanceType: m1.small
Ec2Kernel: unavailable
Ec2Ramdisk: unavailable
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: juju
UpgradeStatus: No upgrade log present (probably fresh install)