TransmogrifierTest: Capture the log

test/pleroma/web/activity_pub/transmogrifier_test.exs

@@ -128,10 +128,11 @@ test "it keeps link tags" do
 
       message = File.read!("test/fixtures/fep-e232.json") |> Jason.decode!()
 
+      assert capture_log(fn ->
                assert {:ok, activity} = Transmogrifier.handle_incoming(message)
-
                object = Object.normalize(activity)
                assert [%{"type" => "Mention"}, %{"type" => "Link"}] = object.data["tag"]
+             end) =~ "Error while fetching"
     end
 
     test "it accepts quote posts" do