问turbogear2快速入门示例的问题

EN

$ virtualenv --no-site-packages -p python2.6 tg2env
$ cd tg2env/
$ source bin/activate
(tg2env)$ easy_install -i http://www.turbogears.org/2.1/downloads/current/index tg.devtools
(tg2env)$ paster quickstart example
(tg2env)$ cd example/
(tg2env)$ python setup.py develop
(tg2env)$ nosetests
(tg2env)$ paster setup-app development.ini
(tg2env)$ paster serve development.ini
(tg2env)$ deactivate

File "/home/starcorn/tg2env/bin/paster", line 9, in <module>
    load_entry_point('PasteScript==1.7.3', 'console_scripts', 'paster')()
  File "/home/starcorn/tg2env/lib/python2.6/site-packages/PasteScript-1.7.3-py2.6.egg/paste/script/command.py", line 84, in run
    invoke(command, command_name, options, args[1:])
  File "/home/starcorn/tg2env/lib/python2.6/site-packages/PasteScript-1.7.3-py2.6.egg/paste/script/command.py", line 123, in invoke
    exit_code = runner.run(args)
  File "/home/starcorn/tg2env/lib/python2.6/site-packages/PasteScript-1.7.3-py2.6.egg/paste/script/appinstall.py", line 68, in run
    return super(AbstractInstallCommand, self).run(new_args)
  File "/home/starcorn/tg2env/lib/python2.6/site-packages/PasteScript-1.7.3-py2.6.egg/paste/script/command.py", line 218, in run
    result = self.command()
  File "/home/starcorn/tg2env/lib/python2.6/site-packages/PasteScript-1.7.3-py2.6.egg/paste/script/appinstall.py", line 456, in command
    self, config_file, section, self.sysconfig_install_vars(installer))
  File "/home/starcorn/tg2env/lib/python2.6/site-packages/PasteScript-1.7.3-py2.6.egg/paste/script/appinstall.py", line 598, in setup_config
    mod.setup_app, command, filename, section, vars)
  File "/home/starcorn/tg2env/lib/python2.6/site-packages/PasteScript-1.7.3-py2.6.egg/paste/script/appinstall.py", line 612, in _call_setup_app
    func(command, conf, vars)
  File "/home/starcorn/tg2env/example/example/websetup/__init__.py", line 17, in setup_app
    load_environment(conf.global_conf, conf.local_conf)
  File "/home/starcorn/tg2env/lib/python2.6/site-packages/TurboGears2-2.1-py2.6.egg/tg/configuration.py", line 581, in load_environment
    setup()
  File "/home/starcorn/tg2env/lib/python2.6/site-packages/TurboGears2-2.1-py2.6.egg/tg/configuration.py", line 392, in setup_genshi_renderer
    from tg.dottednames.genshi_lookup import GenshiTemplateLoader
  File "/home/starcorn/tg2env/lib/python2.6/site-packages/TurboGears2-2.1-py2.6.egg/tg/dottednames/genshi_lookup.py", line 6, in <module>
    from genshi.template import TemplateLoader
ImportError: No module named genshi.template