Smart plugin error while start glances as root

[marcusboon]

Describe the bug
Trying to start glances as root (not matter what mode, e.g. standalone or web) causes a crash and a python stack trace to be displayed

To Reproduce
Steps to reproduce the behavior:

1. Start glances either as the root user directly or using sudo

Expected behaviour
Glances starts normally

Actual behaviour'
Glances crashes with this stack trace:

root@malachor:~# glances
Traceback (most recent call last):
  File "/usr/local/bin/glances", line 8, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.8/dist-packages/glances/__init__.py", line 145, in main
    start(config=config, args=args)
  File "/usr/local/lib/python3.8/dist-packages/glances/__init__.py", line 110, in start
    mode = GlancesMode(config=config, args=args)
  File "/usr/local/lib/python3.8/dist-packages/glances/standalone.py", line 78, in __init__
    self.stats.update()
  File "/usr/local/lib/python3.8/dist-packages/glances/stats.py", line 234, in update
    self._plugins[p].update()
  File "/usr/local/lib/python3.8/dist-packages/glances/plugins/glances_plugin.py", line 993, in wrapper
    ret = fct(self, *args, **kw)
  File "/usr/local/lib/python3.8/dist-packages/glances/plugins/glances_plugin.py", line 1003, in wrapper
    ret = fct(*args, **kw)
  File "/usr/local/lib/python3.8/dist-packages/glances/plugins/glances_smart.py", line 155, in update
    stats = get_smart_data()
  File "/usr/local/lib/python3.8/dist-packages/glances/plugins/glances_smart.py", line 98, in get_smart_data
    devlist = DeviceList()
  File "/usr/local/lib/python3.8/dist-packages/pySMART/device_list.py", line 56, in __init__
    self._initialize()
  File "/usr/local/lib/python3.8/dist-packages/pySMART/device_list.py", line 95, in _initialize
    cmd = Popen([SMARTCTL_PATH, '--scan-open'], stdout=PIPE, stderr=PIPE)
  File "/usr/lib/python3.8/subprocess.py", line 854, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/usr/lib/python3.8/subprocess.py", line 1583, in _execute_child
    and os.path.dirname(executable)
  File "/usr/lib/python3.8/posixpath.py", line 152, in dirname
    p = os.fspath(p)
TypeError: expected str, bytes or os.PathLike object, not NoneType

Desktop (please complete the following information):

• OS: Pop_OS! 20.04 (Ubuntu 20.04)

• Glances Version

{ ~ }  » glances -V                                                                                                                                                                       ~  
Glances v3.1.6.1 with PsUtil v5.8.0
Log file: /home/marcus/.local/share/glances/glances.log

• Glances logs file

{ ~ }  » tail -10 ~/.local/share/glances/glances.log                                                                                                                                      ~  
2021-02-01 11:08:11,188 -- INFO -- Search glances.conf file in /home/marcus/.config/glances/glances.conf
2021-02-01 11:08:11,188 -- INFO -- Search glances.conf file in /etc/glances/glances.conf
2021-02-01 11:08:11,189 -- INFO -- Read configuration file '/etc/glances/glances.conf'
2021-02-01 11:08:11,193 -- INFO -- Start GlancesStandalone mode
2021-02-01 11:08:11,293 -- WARNING -- Wifi lib is not compliant with Python 3, Wifi plugin is disabled
2021-02-01 11:08:40,470 -- INFO -- Stop Glances (keypressed: 113)
2021-02-01 12:38:28,003 -- INFO -- Start Glances 3.1.6.1
2021-02-01 12:38:28,003 -- INFO -- CPython 3.8.5 and psutil 5.8.0 detected
2021-02-01 12:38:52,303 -- INFO -- Start Glances 3.1.6.1
2021-02-01 12:38:52,303 -- INFO -- CPython 3.8.5 and psutil 5.8.0 detected

Additional context
Python is at version 3.8.5 for both my user and the root user (not using any fancy virtual env setup)

{ ~ }  » python --version                                                                                                                                                                 ~  
Python 3.8.5
{ ~ }  » sudo python --version                                                                                                                                                            ~  
Python 3.8.5

[nicolargo]

Hum...
Can you try to run Glances without the smart plugin (--disable-plugin smart)?

[marcusboon]

Ok it works without the smart plugin. Weird.

[nicolargo]

I will have a look as soon as possible.

Thanks for the issue report!

[marcusboon]

Cheers! Thanks for looking into it :)

[nicolargo]

Corrected (catched) in last commit on the DEVELOP branch