Chromedriver has switched to a new versioning system that matches Chrome’s version numbers.
The Ruby browsers images determine which version of Chromedriver to install by requesting https://chromedriver.storage.googleapis.com/LATEST_RELEASE, e.g.:
But this URL no longer returns the latest version:
The https://chromedriver.storage.googleapis.com/LATEST_RELEASE file is a legacy leftover from the old release model, and will stay at 2.46 for the next few months (to support apps that haven’t been updated to use the new version numbers), and then removed completely.
https://groups.google.com/forum/#!topic/chromedriver-users/8VmMaFjs1cg
Could the build images be updated to install the latest Chromedriver version?