Sorry, I just reproduced your issue, it seems that our docs are not up to date, please, can you try this new approach?
sudo RAILS_ENV=production bundle exec rails c
After that, a new prompt (
irb(main):001:0>) should appears, once appears this console, run:
u = User.find_by_username("YOUR_USERNAME")
u.email = "YOUR_NEW_EMAIL_ADDRESS"
YOUR_NEW_EMAIL_ADDRESS placeholders with your real data. Now, you should be able to access using this new email.
Please let us know if this solves the issue.
Carlos R. Hernández