Say what the graph and the load path each hold

data.go

@@ -215,8 +215,8 @@ func checkScope(s nodeScope) error {
 
 // checkRenders runs the per-node fences over a scope, each over the whole scope
 // before the next, so which of several broken nodes is reported does not depend on
-// the walk. It runs after checkNoCycles, whose guarantee is what lets the walks
-// terminate.
+// the walk. Its walks terminate only where nothing renders itself, so run it over a
+// loaded tree after checkNoCycles.
 func checkRenders(s nodeScope) error {
 	mem := reachMemo{}
 	if err := s(func(path string, n node) error { return repeatCheck(path, n, mem) }); err != nil {