Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 801, in on_edit_clicked
    if dialog.run() == Gtk.ResponseType.OK:
  File "/usr/lib/python2.7/dist-packages/softwareproperties/gtk/DialogEdit.py", line 121, in run
    index = self.sourceslist.list.index(self.source_entry)
ValueError: <aptsources.sourceslist.SourceEntry object at 0x218cc10> is not in list