According to some bugs (http://dev.deluge-torrent.org/ticket/958, http://dev.deluge-torrent.org/ticket/1868), improved torrent searching/filtering has been added to 1.4-Dev. I installed 1.4 from the head of git and while I see a search icon in the top bar clicking it does nothing. Ctrl-F does nothing either. They don't even generate any debug logging.
Is search/filter it expected to work in the head of git now or is it known to be broken?