"Open Invitations" and akonadi_search_resource

[Glen Ditchfield]

In KOrganizer, when I select the "Update Folder" item from the right-
click menu of the "Open Invitations" search folder, Akonadi (not 
KOrganizer) prints

  org.kde.pim.akonadicontrol: Agent instance with identifier
    "akonadi_search_resource"  does not exist

Whatever happened to akonadi_search_resource?  I haven't found any 
information about it.  Was it something that wasn't ported forward 
during some major upgrade?  Was there ever a version of KOrganizer where 
"Open Invitations" worked?  Is there any potentially useful old code or 
documentation available somewhere?