// repeat in irc
						nick := self.name_convert(chat.System.matrix, sender)
						if room := self.matching_irc_channel(nick, room_id) {
							self.chat.say(chat.System.irc, nick, '', room, body)
						} else {
							println('warning: no irc channel found for $nick ${room_id}. msg dropped: $body')

						if alias_room := self.matrix.room_alias(room_id) {
							nick := self.name_convert(chat.System.matrix, sender)
							if room := self.matching_irc_channel(nick, alias_room.name) {
								// repeat in irc
								self.chat.say(chat.System.irc, nick, '', room, body)
							} else {
								println('warning: no irc channel found for $nick ${alias_room}. msg dropped: $body')
							}

			println('sync_rooms: joining $room.id')
			_, code := self.matrix.join(room.id) or {
				println('matrix.join fail $err')
				continue
			}
			if code == 200 {
				self.matrix.joined_rooms.add(room)
				self.admin_say('matrix: room $room joined')
			} else if code == 403 {
				println('sync_rooms: not invited to $room.name')
			}

		println('sync_rooms: joining $room.id')
		_, code := self.matrix.join(room.id) or {
			println('matrix.join fail $err')
			continue
		}
		if code == 200 {
			self.matrix.joined_rooms.add(room)
			self.admin_say('matrix: room $room joined')
		} else if code == 403 {
			println('sync_rooms: not invited to $room.name')
		}