# File lib/nanoc/cli/commands/sync.rb, line 13
    def run
      # Check arguments
      if arguments.size != 0
        raise Nanoc::Errors::GenericTrivial, "usage: #{command.usage}"
      end

      # Make sure we are in a nanoc site directory
      self.require_site

      # Update all syncable data sources
      self.site.data_sources.each do |data_source|
        unless data_source.method(:sync).owner == Nanoc::DataSource
          puts "Syncing #{data_source.config[:type]} data source: #{data_source.items_root}"
          data_source.sync
        end
      end
    end