I can't seem to edit entry details all of a sudden: in this Products section (and only this one section), the page title and "Current Version" button will render, but the rest of the page is missing.
The only clue is this line from Craft's log:
[31-Jul-2014 19:07:36 UTC] PHP Fatal error: Maximum function nesting level of '100' reached, aborting! in /Users/gob/projects/gobias/craft/app/vendor/twig/twig/lib/Twig/Node.php on line 140
I've loaded earlier MySQL backups, restarted MAMP Pro (PHP 5.5.10), cleared Craft's caches, tried different browsers and machines, and the problem persists.