On the Lakion blog there's a post showing you how to debug your application's Behat tests easily as a part of your continuous integration process. In thieir case, they were trying to figure out why builds were breaking on a Travis-CI build instance.

Debugging Behat scenarios while using Mink to simulate the user is not always an easy job. Especially, if they are run on Continuous Integration server. That is why I came up with an idea to make it easier. During repairing our javascript test suite on Sylius everything went as bad as it could go. There were many errors that happened on Travis, but I was not able to reproduce them locally. [...] MinkDebugExtension was written to speed up that boring and tiring part of debugging on CI server. It consists of two parts: Behat extension and useful scripts.

The extension fires after failed steps and makes a log of the issue with content needed to recreate the issue (including possible screenshots). He also describes the scripts that come with it to help you browse through the results, uploading the resulting logs and screenshots to a place for public consumption.