+>>>> I'm not sure that even that is *quite* right: if your `trail` takes
+>>>> pagespecs as arguments, then it's potentially evaluating those pagespecs
+>>>> before all pages have been scanned, which could mean it lists pages
+>>>> which matched the spec before a recent change, or doesn't list pages
+>>>> which didn't previously match the spec but do now.
+>>>>
+>>>> In version 3 of [[plugins/contrib/trail]] I ended up storing
+>>>> uninterpreted pagespecs and links at scan time, and evaluating them the
+>>>> first time a page is built. I *think* that's sufficiently lazy to give
+>>>> the right answer... --[[smcv]]
+