tahoe-lafs needs "mock" but the .deb doesn't declare a dependency on python-mock

[Zooko Wilcox-O'Hearn]

Binary package hint: tahoe-lafs

$ tahoe --version
Traceback (most recent call last):
  File "/usr/bin/tahoe", line 6, in <module>
    from pkg_resources import load_entry_point
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2671, in <module>
    working_set.require(__requires__)
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 654, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 552, in resolve
    raise DistributionNotFound(req)
pkg_resources.DistributionNotFound: mock

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: tahoe-lafs 1.8.2-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-8.42-virtual 2.6.38.2
Uname: Linux 2.6.38-8-virtual i686
Architecture: i386
Date: Fri May 13 20:08:23 2011
Ec2AMI: ami-ccf405a5
Ec2AMIManifest: (unknown)
Ec2AvailabilityZone: us-east-1a
Ec2InstanceType: t1.micro
Ec2Kernel: aki-407d9529
Ec2Ramdisk: unavailable
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: tahoe-lafs
UpgradeStatus: Upgraded to natty on 2011-05-13 (0 days ago)