This post announces some breaking changes for build farms based on ros-infrastructure/buildfarm_deployment and ros-infrastructure/buildfarm_deployment_config.
The canonical ROS buildfarm at build.ros.org has recently been migrated to Ubuntu Xenial 
Over the next couple of weeks I’ll be preparing a guide with specific changes and suggestions for implementing the migration based our experience migrating the canonical farm. There will also be instructions for keeping your instances targeting the current Trusty-based farm once the master branch receives the Xenial updates.
If you’re interested in reading ahead you can check out the following pull requests on GitHub
I don’t have an exact hard deadline for when the master branch will move to xenial only as it depends somewhat on the stability of the new build farm and the amount of time I can allocate to writing the migration guide but expect at least two weeks’ notice and I don’t expect to have it done before ROSCon.
On that note, I’ll be at ROSCon and it’ll be my first time so if you want to talk about the buildfarm or other ROS infrastructure there hit me up!