Error on build: No module named stats

This is revision 654:

running install
running build
running build_py
running build_scripts
running build_credits
Traceback (most recent call last):
  File "setup.py", line 204, in <module>
    'check': Check}
  File "/usr/lib/python2.6/distutils/core.py", line 152, in setup
    dist.run_commands()
  File "/usr/lib/python2.6/distutils/dist.py", line 975, in run_commands
    self.run_command(cmd)
  File "/usr/lib/python2.6/distutils/dist.py", line 995, in run_command
    cmd_obj.run()
  File "/usr/lib/python2.6/distutils/command/install.py", line 577, in run
    self.run_command('build')
  File "/usr/lib/python2.6/distutils/cmd.py", line 333, in run_command
    self.distribution.run_command(command)
  File "/usr/lib/python2.6/distutils/dist.py", line 995, in run_command
    cmd_obj.run()
  File "/usr/lib/python2.6/distutils/command/build.py", line 134, in run
    self.run_command(cmd_name)
  File "/usr/lib/python2.6/distutils/cmd.py", line 333, in run_command
    self.distribution.run_command(command)
  File "/usr/lib/python2.6/distutils/dist.py", line 995, in run_command
    cmd_obj.run()
  File "setup.py", line 56, in run
    from bzrlib.plugins.stats import find_credits
ImportError: No module named stats