One used to be able to download Vagrant boxes to debug Travis builds (for GitHub projects for instance). Apparently, this is no longer possible, so how do people currently debug
Unfortunately, there is no good solution for testing travis-ci builds locally at the moment. The closest thing I can recommend is a Ubuntu 12.04 vagrant vm and to provision it with the Travis chef cookbooks from here. This will solve most use cases as most of the time the test failures are not from the travis software (Though when it is you're in tough luck, as most Travis software depends on the other pieces of Travis software, making it fairly difficult to set up) but from the underling OS (Ubuntu) and software such as ruby and ruby gems.
One way to inspect the build (not to debug, sorry) is to send the build logs to another server on failure.
Here is an example:
after_failure
- sudo tar -czf /tmp/build-${TRAVIS_BUILD_NUMBER}-logs.tgz your-application-logs/
- scp /tmp/build-${TRAVIS_BUILD_NUMBER}-logs.tgz travis@your-server.com:~/logs
You could send them via email, store them on a storage server or whatever.
These logs would be useful to you if you run your tests in a debug mode and include our own logs as well in the tarball.
I had a crack at making a docker file for JVM builds here which works well for me. It is based of the travis published containers and utilises the Travis CLI and Travis Build projects to be able to run your .travis.yml file within a docker container.
A built JVM image is on docker hub.