`fuubar_auto_refresh` config undefined

[vinnydiehl]

I'm getting a failure when using the fuubar_auto_refresh option. In spec_helper.rb I have:

RSpec.configure do |config|
  # my configuration

  config.add_formatter "Fuubar"
  config.fuubar_auto_refresh = true
end

Output when I run the test suite is:

An error occurred while loading spec_helper.
Failure/Error: config.fuubar_auto_refresh = true

NoMethodError:
  undefined method `fuubar_auto_refresh=' for #<RSpec::Core::Configuration:...........>

I'm using Ruby 3.2.0, it's a Rails 7 app running on up-to-date Arch Linux. Without this configuration option Fuubar works perfectly.