When loading the initial “virgin” wiki, the process stops at the page “Help/Categories”.
The reason for this is that this page contains a reference to an image, and therefore LinkImage in stdlib.php is called, esp. the following portion:
$size = @getimagesize($request->get('DOCUMENT_ROOT').urldecode($url));
$request is undefined in this function.
I'm attaching a simple patch for this issue that allows the process to complete successfully.