find_command (Gem::CommandManager)

    # File lib/rubygems/command_manager.rb, line 136
      def find_command(cmd_name)
        possibilities = find_command_possibilities cmd_name
        if possibilities.size > 1 then
          raise "Ambiguous command #{cmd_name} matches [#{possibilities.join(', ')}]"
        elsif possibilities.size < 1 then
          raise "Unknown command #{cmd_name}"
        end

        self[possibilities.first]
      end