These two blog posts describe a way to debug failing regression tests using the same VM image that Travis-CI uses. It's a great idea, but the download link given there is out-of-date: the .box
files they link to are 32-bit images, and Travis-CI now uses 64-bit images.
Where can I download the 64-bit images that Travis-CI now uses?
Update: Just in case it's useful: These days I use CircleCI for continuous integration, which offers easy-to-use ssh access to the build container. That makes debugging a troublesome CI setup way easier. Now there's no need to replicate the CI environment locally, as I was trying to do when I originally submitted this question.