```
  File "/home/john/qtpyvcp/qtpyvcp/widgets/display_widgets/notification_widget.py", line 31, in __init__
    self.clock_channel = getPlugin("clock")
  File "/home/john/qtpyvcp/qtpyvcp/plugins/__init__.py", line 73, in getPlugin
    raise ValueError("Failed to find plugin for '{}' protocol.".format(protocol))
ValueError: Failed to find plugin for 'clock' protocol.