Debug EntityFieldQuery?
It's a wee bit of a hack, but you could add a tag to any EntityFieldQuery you're interested in printing the query for, then implement hook_query_alter() to intercept it when it's a standard SelectQuery, then cast it to string for debugging:

function MYMODULE_query_alter($query) {
  if ($query-&gt;hasTag('efq_debug')) {
    dpm((string)$query);
  }
}

$q = new EntityFieldQuery;
$q-&gt;entityCondition('entity_type', 'node')
  -&gt;addTag('efq_debug')
  -&gt;execute();


It's a bit of a hack but does the trick. The output for the above is:

SELECT node.nid AS entity_id, node.vid AS revision_id, node.type AS bundle, :entity_type     
AS entity_type
FROM {node} node


Presumably this will also only work when using MySQL as the field storage system.