Why does var_dump(array) result in a 500 error in Magento?

Question

I'm trying to see what is inside all the objects of the Magento system, but when I try to var_dump the $_links variable (containing all information needed for rendering the links in the header of every page) from inside the top links template, my server responds with a 500 error. Anyone know why?

Answer 1

Dumps of Magento objects get a bit messy, even if there isn't recursion there is all the EAV and cache stuff. When you have an array you'll need to dump them individually:

foreach ($_links as $object) {
    var_dump($object->debug());
}

Answer 2

It's likely a memory error. Magento's object can be huge, and the default var_dump implementation in PHP isn't that smart about some of the circular references.

Install xDebug is a must. With xDebug, the var_dump function gets a lot smarter, and the memory limit exhausted errors mostly go away.