# File lib/rbot/plugins.rb, line 739
    def help(topic="")
      case topic
      when /fail(?:ed)?\s*plugins?.*(trace(?:back)?s?)?/
        # debug "Failures: #{@failed.inspect}"
        return _("no plugins failed to load") if @failed.empty?
        return @failed.collect { |p|
          _('%{highlight}%{plugin}%{highlight} in %{dir} failed with error %{exception}: %{reason}') % {
              :highlight => Bold, :plugin => p[:name], :dir => p[:dir],
              :exception => p[:reason].class, :reason => p[:reason],
          } + if $1 && !p[:reason].backtrace.empty?
                _('at %{backtrace}') % {:backtrace => p[:reason].backtrace.join(', ')}
              else
                ''
              end
        }.join("\n")
      when /ignored?\s*plugins?/
        return _('no plugins were ignored') if @ignored.empty?

        tmp = Hash.new
        @ignored.each do |p|
          reason = p[:loaded] ? _('overruled by previous') : _(p[:reason].to_s)
          ((tmp[p[:dir]] ||= Hash.new)[reason] ||= Array.new).push(p[:name])
        end

        return tmp.map do |dir, reasons|
          # FIXME get rid of these string concatenations to make gettext easier
          s = reasons.map { |r, list|
            list.map { |_| _.sub(/\.rb$/, '') }.join(', ') + " (#{r})"
          }.join('; ')
          "in #{dir}: #{s}"
        end.join('; ')
      when /^(\S+)\s*(.*)$/
        key = $1
        params = $2

        # Let's see if we can match a plugin by the given name
        (core_modules + plugins).each { |p|
          next unless p.name == key
          begin
            return p.help(key, params)
          rescue Exception => err
            #rescue TimeoutError, StandardError, NameError, SyntaxError => err
            error report_error("#{p.botmodule_class} #{p.name} help() failed:", err)
          end
        }

        # Nope, let's see if it's a command, and ask for help at the corresponding botmodule
        k = key.to_sym
        if commands.has_key?(k)
          p = commands[k][:botmodule]
          begin
            return p.help(key, params)
          rescue Exception => err
            #rescue TimeoutError, StandardError, NameError, SyntaxError => err
            error report_error("#{p.botmodule_class} #{p.name} help() failed:", err)
          end
        end
      end
      return false
    end