Recover from errors in custom extractors

lib/frenzy/pipeline/scrape_stage.ex

@@ -89,7 +89,19 @@ defmodule Frenzy.Pipeline.ScrapeStage do
 
       module_name ->
         html_tree = Floki.parse(body)
-        apply(String.to_existing_atom("Elixir." <> module_name), :extract, [html_tree])
+
+        try do
+          apply(String.to_existing_atom("Elixir." <> module_name), :extract, [html_tree])
+        rescue
+          e ->
+            Logger.error(
+              "Encountered error extracting article content from '#{url}' with #{module_name}, falling back to default"
+            )
+
+            Logger.error(Exception.format(:error, e, __STACKTRACE__))
+
+            {:ok, Readability.article(body)}
+        end
     end
     |> case do
       {:ok, html} ->