if alias_room := self.matrix.room_alias(room.id) {
			println('sync_rooms: joining $alias_room.id')
			_, code := self.matrix.join(alias_room.id) or {

			println('sync_rooms: joining $room.id')
			_, code := self.matrix.join(room.id) or {

		} else {
			match err {
				matrix.RoomAliasErrNotFound {
					println('sync_rooms: matrix room $room unknown/no alias')
				}
				else {
					// some other error. skip this room
				}
			}
		}