swhscheduler@scheduler0:~$ /usr/bin/swh scheduler --config-file /etc/softwareheritage/backend/elastic.yml task archive
Traceback (most recent call last):
  File "/usr/bin/swh", line 11, in <module>
    load_entry_point('swh.core==0.11.0', 'console_scripts', 'swh')()
  File "/usr/lib/python3/dist-packages/swh/core/cli/__init__.py", line 185, in main
    return swh(auto_envvar_prefix="SWH")
  File "/usr/lib/python3/dist-packages/click/core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/usr/lib/python3/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python3/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python3/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python3/dist-packages/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/lib/python3/dist-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/usr/lib/python3/dist-packages/swh/scheduler/cli/task.py", line 690, in archive_tasks
    before = now.shift(weeks=-1).format("YYYY-MM-DD")
AttributeError: 'datetime.datetime' object has no attribute 'shift'