vendor/plugins/has_many_polymorphs/lib/has_many_polymorphs/dependencies.rb:8: Dependencies is not a module (TypeError)

This is dued to a Rails 2.1.1 refactoring in the location of the ActiveSupport::Dependencies module.
Copy paste the following code to your /has_many_polymorphs/lib/has_many_polymorphs/dependencies.rb to fix the problem:

module ActiveSupport
  module Dependencies
    
    mattr_accessor :injection_graph
    self.injection_graph = Hash.new([])

    # Add a dependency for this target.
    def inject_dependency(target, *requirements)
      target, requirements = target.to_s, requirements.map(&:to_s)    
      injection_graph[target] = ((injection_graph[target] + requirements).uniq - [target])
      requirements.each {|requirement| mark_for_unload requirement }
      _logger_debug "injection graph: #{injection_graph.inspect}" if Dependencies.log_activity
    end

    # Make sure any dependent constants of the constants added by yield are reloaded.
    def new_constants_in_with_injection(*descs, &block) # chain

      if Dependencies.log_activity
        _logger_debug "autoloaded constants: #{autoloaded_constants.inspect}"
        _logger_debug "explicitly unloadable constants: #{explicitly_unloadable_constants.inspect}" 
      end
    
      returning(new_constants_in_without_injection(*descs, &block)) do |found|
        _logger_debug "new constants: #{found.inspect}" if Dependencies.log_activity and found.any?
        found.each do |constant|
          injection_graph[constant].each do |requirement| 
            requirement.constantize
            _logger_debug "constantized #{requirement}" if Dependencies.log_activity
          end
        end    
      end
    end
    alias_method_chain :new_constants_in, :injection
   
  end
end

I am using the plugin has_many_polymorphs to manage tags in languages. An event has a category which is in reality a tag we translate in 7 languages ...

I inherited this plugin from the previous developper and I am looking forward to replace it by acts_as_taggable_on_steroids !