Starting today, all Linux builds on travis-ci.org or travis-ci.com will now be routed to the virtual-machine based infrastructure. As you may have seen on the blog, we have been in the process of deprecating the container-based infrastructure, in favor of our virtual-machine-based platform to provide a better, clearer build configuration experience.
The virtual-machine based environment has all the same tools as the container-based environment, along with better compute resources and support for building Docker containers. IP addresses for the workers running builds are different between the two infrastructures. If you safelist Travis CI IP addresses for your container-based builds, we recommend updating those values.
Of course, if you have any questions, feel free to contact us or let us know on the community forum. Thanks so much!