Hey there!
Love the love for Sentry 
The stacktrace you linked is coming an addition we made in order to try and eliminate confusion about whether this is raven.js related bug - see https://github.com/getsentry/raven-js/pull/847.
What’s happening is we are catching a non-error object, from which we cannot normally derive a stack trace. This can happen when you throw a non-error object.
Something like throw "error"; or throw {foo:'bar'};
When Raven.js can’t derive a stack trace, it attempts to generate a “synthetic trace” when this occurs. Often this synthetic trace can lead you back to the origin of where the error was thrown. But not always. If it’s an internal browser error or 3rd-party extension, it’s possible the trace will end with Raven.js.
Hopefully that sheds some 