"memory errors while indexing"

I believe that I have found a memory leak issue in content.module which will have an impact on those using apachesolr, especially if they are indexing many nodes (1000s) at once. You can read the Circular reference - Memory Leak report for the details.

In order to work around this I added the following to the bottom of apachesolr_node_to_document(), just before the document is returned:

unset($node->content);   // Hack: Need to unset content so that circular ref is removed
return $document;

This has the effect of removing the circular reference, making memory stable for indexing large amounts of nodes. So, this isn't really a bug with apachesolr, rather a little hack which may be of use for some people.