Don't forget to iterate over the populate generator.

volatility/framework/renderers/__init__.py

@@ -240,7 +240,7 @@ class TreeGrid(interfaces.renderers.TreeGrid):
            for every node we descend further down
         """
         if not self.populated:
-            self.populate()
+            list(self.populate())
 
         # Find_nodes is path dependent, whereas _visit is not
         # So in case the function modifies the node's path, find the nodes first

volatility/framework/renderers/text.py

@@ -53,4 +53,4 @@ class QuickTextRenderer(interfaces.renderers.Renderer):
             accumulator.write("\n")
             return accumulator
 
-        grid.populate(visitor, outfd)
+        list(grid.populate(visitor, outfd))