If you're bug hunting with var_dump(), you are not adverse to temporarily hacking at source code to add debug statements at weird places.
As this method has "debug" in it, it's purpose is uncontroversial bughinting. Isn't it?
How many objects are in a avarage orm to temporarily be hacked? In comparison to var_dump($wholeObjectGraph) justifiable?
You're probably also hacking out all your normal exception handling and output formatting to get the dump to display on screen. So why wouldn't you be prepared to hack this too?
Why display on screen? $foo->log(print_r($bar, true)); is impossible too.