The Special:Ask page is not working on my Semantic Mediawiki installation:
http://ropewiki.com/index.php/Special:Ask

When requested, it returns no content which I assume implies a PHP exception somewhere.  Is there a better way to go about debugging this apart from trying to figure out good places to insert print statements?

Versions of everything installed are of course listed here:
http://ropewiki.com/index.php/Special:Version

...and Special:Ask queries themselves seem to work -- for instance, this link from an auto-generated "further results" link:
http://ropewiki.com/index.php/Special:Ask/-5B-5BCategory:Canyons-5D-5D/-3FHas-20KML-23Yes,No%3DMap/-3FIs-20explored-23Yes,No%3DExplored/format%3Dtable/limit%3D10/sort%3DModification-20date/order%3Ddescending/offset%3D10

To see one of these "further results" auto-generated links, see the bottom of
http://ropewiki.com/index.php/Beta

Thanks!
--Ben