Viomi S9 does not expose hv_wer

[rytilahti]

Discussed in #1081

^{Originally posted by fokcuk June 24, 2021}
Hi
I am trying to do some basic cli testing of commands as I am not that good at Python to write code from scratch.
I have a Viomi S9 vacuum. When I try to run this command I get an error about hw_ver:

─# miiocli viomivacuum --ip 192.168.1.124 --token 78326372527131116c6a436a4a6c3744 info                                                                 2 ⨯
Traceback (most recent call last):
  File "/usr/local/bin/miiocli", line 8, in <module>
    sys.exit(create_cli())
  File "/usr/local/lib/python3.9/dist-packages/miio/cli.py", line 63, in create_cli
    return cli(auto_envvar_prefix="MIIO")
  File "/usr/local/lib/python3.9/dist-packages/miio/click_common.py", line 59, in __call__
    return self.main(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/usr/lib/python3/dist-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python3/dist-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python3/dist-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/lib/python3/dist-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python3.9/dist-packages/miio/click_common.py", line 285, in wrap
    result_msg = result_msg_fmt.format(**kwargs)
  **File "/usr/local/lib/python3.9/dist-packages/miio/device.py", line 88, in hardware_version
    if self.data["hw_ver"] is not None:
KeyError: 'hw_ver'**

I have seen this error in another project that is connecting to Xiaomi devices. What I ended up doing there was to modify device.py and comment out all lines that tried to check for hardware_version.

Just trying to get to it working one line at a time and would appreciate some help