At work we were stumped by a simple link that upon clicking didn’t have the browser request the target page. Our supplier investigated using VisualEvent, a bookmarklet-initiated javasript-tool that goes through a page and visualizes all events on DOM nodes. The developer released VisualEvent 2 a couple of days ago (also on GitHub), which I played around with for a bit and it really is great for debugging purposes!
The culprit for the “broken” link by the way was a bug in an old version of SmoothScroll, a jQuery-plugin by fellow Belgian Mathias Bynens which ensures smooth scrolling when clicking on a in-page link. The plugin did check if the link was to an anchor on the same page, but it had already prevented the default action before that check was made, resulting in the broken link. The current version of the plugin does the check before the default action is prevented, so all is well, your weekend can start. Enjoy!