I wrote this test, and I confirm, it doesn't work. I'll see if I can sort this out today ...
start_at = village locations { village : location "You are in a village" ; river : location "You are next to a river" ; lake : location "You are next to the lake" ; } objects { flippers : object "some flippers" start_at = "village"; toaster : object "a toaster" start_at = "village" ; } connections { from, direction, to = [ village, north, river, village, south, lake, ] } zones { wet_region : zone { locations= [ river, lake ] } } barriers { block_wet_region : block { location = wet_region message = It's too wet to go there. Maybe some make sure you have some flippers? block_when_not_carried = flippers show_blocked_exit = false } }