Using "show selection" before selecting anything raises a Python exception:

$ mhsh
mhsh> show selection 
% 'NoneType' object is not iterable

Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/matahari/shell/interpreter/interpreter.py", line 81, in onecmd
    return cmd.Cmd.onecmd(self, line)
  File "/usr/lib64/python2.7/cmd.py", line 219, in onecmd
    return func(arg)
  File "/usr/lib/python2.7/site-packages/matahari/shell/interpreter/command.py", line 191, in __call__
    return self.do(*args)
  File "/usr/lib/python2.7/site-packages/matahari/shell/mode.py", line 77, in show_selection
    self.writelist(self.state.objects)
  File "/usr/lib/python2.7/site-packages/matahari/shell/mode.py", line 49, in writelist
    self.write(*[str(o) for o in objects])
TypeError: 'NoneType' object is not iterable