Ruby on Rails: Xcode: Instruments: Trace/BPT trap? What is it, and how do I fix it?

So, I wanted to test my RoR app for memory leaks, and I was all like "Hey, Xcode has a tool for that"..

So... I run the RoR server

Then The moment I tell instruments to attach to the process, it dies, and tells me Trace/BPT trap

What is Trace/BPT trap

And how do I test my app for memory leaks?

I've never heard of testing a Rails app with XCode before. Neat idea.

Debugging memory leaks is a pretty broad topic, but here's a link to the RailsGuides suggestions: http://guides.rails.info/debugging_rails_applications.html#debugging-memory-leaks

Also check out New Relic: http://www.newrelic.com/