Currently our supported Ruby version in Sufia 7 is 2.3.1
Rollback and upgrade
We are manually building Ruby and not using the packaged version of Ruby (too old), rvm or a similar tool (I assume because those tools cause issues with Hydra/Sufia? -Dan). Thankfully upgrading/downgrading ruby is easy enough.
Run the following:
whereis ruby
rm -r (results from prior command)
That should remove the old versions
Then go grab the desired Ruby version from the Ruby site and follow the normal manual install commands.
Once installed you'll need to add bundler as well
sudo gem install bundler