undefined_method `author=` for Quarto::Module when running rake deliverables

[balinterdi]

I tried to run rake deliverables with the following Rakefile:

require 'quarto'

Quarto.configure do |config|
  config.author          = "Avdi Grimm"
  config.title               = "Confident Ruby"
end

Just as it is prescribed in the README, but got the error message in the subject line.

What am I doing wrong?

[saturnflyer]

Is this still valid? If so, can you provide the stack trace?

[balinterdi]

Yes, this is still valid. It has the following stacktrace:

✓ /tmp/quarto » rake -T
rake aborted!
undefined method `author=' for Quarto:Module
/private/tmp/quarto/Rakefile:4:in `block in <top (required)>'
/private/tmp/quarto/Rakefile:3:in `<top (required)>'