Using old and EOL versions of Ruby now generate warnings
Change effective on 15 October 2019
If your application is using a version of MRI Ruby that is below the latest released patch level, you’ll now receive a warning on deploy in the build output. For example, if you are using 2.3.3, you’ll be encouraged to upgrade to the latest in the series which is 2.3.8.
In addition to the version warning, you’ll now receive warnings when you’re using a version of Ruby that may be EOL (End of Life) soon or is already EOL. Ruby Core officially supports up to 3 releases of Ruby at a time. For example, when 2.7 is released, then the supported versions will be 2.7.x, 2.6.x, and 2.5.x. Our support mirrors Ruby Core support. You can see the latest versions of Ruby available on our Ruby support page.
Right now you’ll receive a warning indicating that your version of Ruby is close to being EOL if you’re using 2.4.x. If you’re using 2.3.x or older, you’ll receive a warning indicating that your version is already EOL and we will not be providing support or security patches for the version.
We highly recommend staying on a non-EOL version of Ruby and using the latest patch release as these versions contain the most up to date security and bug fixes.