I haven’t used Ubuntu much recently after switching several systems to Manjaro, but had to set up a laptop with XUbuntu 17.04. That came with Emacs 24.5 as the default emacs package, and as skeeto pointed out in the comments, with a separate emacs25 package for Emacs 25.1. I tend to run the latest release Emacs everywhere out of habit, so I revisited my build instructions to build a current Emacs on Ubuntu and its derivates. The good news is that in thanks to some changes in the Emacs build, the build is as straightforward as it used to be prior to the combination of Ubuntu 16.10 and Emacs 25.1. In other words, no need to remember to switch off PIE as was necessary when building GNU Emacs 25.1 on Ubuntu 16.10.