I'm building a gem that uses rails-assets-growl gem. This gem can be added to my Gemfile using a different source than 'https://rubygems.org' like this:
source 'https://rails-assets.org' do
  gem 'rails-assets-growl'
end
This works fine in development mode. But, when I publish my gem in rubygems.org growl gem is not included as dependency.
I think, this is beacuse I need to specify the
https://rails-assets.orgsource in gemspec instead of Gemfile. But, I'm not sure.
So, the question is:
How can I specify a source for a gem in gemspec file?

 
    