I've done this so many times, and I keep forgetting what exactly needs to be done. So I decided to write it down. Enjoy!

You have a few files to update:

  • .ruby-version -- tells various systems (e.g. rvm) which ruby version to use automatically
  • Gemfile -- update the ruby line toward the top of the file

Once that's done, you'll need to reinstall stuff. Start by installing the new ruby version in rvm:

$ rvm install "ruby-2.6.6"

Then you'll need to install the bundler for the new ruby version. Grab the bundler version from the Gemfile.lock, search for BUNDLED WITH. At the time of writing, that was 2.1.4. Then you install it:

$ gem install bundler:2.1.4

Once that's done, run bundler to install all your gems for the newly installed ruby version:

$ ruby -v
# should be the one you just installed, e.g. 2.6.6
# if not, reload your shell

$ bundle

Lastly, you'll want to quit and re-open RubyMine to let it work its magic with indexing the new ruby SDK and its gems. Your settings should now point to the new SDK:

And with that, you're done!