Bizarre recursion error+example

http://johnabbe.wagn.org/wagn/workplay gets a SystemStackError, apparently infinitely recursing, but there's no clear reason for it to do so, it just includes a card (in line view) which displays fine itself
 - http://johnabbe.wagn.org/wagn/processarts

Likely the same/similar error is happening on my Recent Changes and http://johnabbe.wagn.org/wagn/all_tags