propel example bug with query_cache

build.properties

# Project name
propel.project = OpenSondage

# Database driver
propel.database                 = mysql
propel.mysql.tableType          = MyISAM
propel.mysql.tableEngineKeyword = ENGINE
propel.tablePrefix              =

#################################################
#
#       DON'T EDIT AFTER THIS LINE
#
#################################################

# Directory
propel.conf.dir           = ${propel.project.dir}
propel.runtime.conf.file  = runtime-conf.xml
propel.phpconf.dir        = ${propel.project.dir}
propel.schema.dir         = ${propel.project.dir}
propel.output.dir         = ${propel.project.dir}/model
propel.php.dir            = ${propel.output.dir}/classes
propel.sql.dir            = ${propel.output.dir}/sql

# Schema options
propel.packageObjectModel     = true
propel.namespace.autoPackage  = true
propel.schema.validate        = true

# Generate options
propel.addGenericAccessors          = true
propel.addGenericMutators           = true
propel.addTimeStamp                 = false
propel.addValidateMethod            = true
propel.addIncludes                  = false
propel.addHooks                     = true
propel.basePrefix                   = Base
propel.useLeftJoinsInDoJoinMethods  = true

# Date
propel.useDateTimeClass       = true
propel.dateTimeClass          = DateTime
propel.defaultTimeStampFormat = Y-m-d H:i:s
propel.defaultDateFormat      = %x

index.php

<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);

try {
// Include the main Propel script
require_once __DIR__.'/vendor/propel/runtime/lib/Propel.php';

// Initialize Propel with the runtime configuration
Propel::init(__DIR__."/OpenSondage-conf.php");

// Add the generated 'classes' directory to the include path
set_include_path(__DIR__."/model/classes" . PATH_SEPARATOR . get_include_path());

$poll = OpenSondage\Database\PollQuery::create()->findOne();

var_dump($poll);
} catch (Exception $e) {
  var_dump($e->getMessage());
}

schema.xml

<?xml version="1.0" encoding="UTF-8"?>
<database name="opensondage" defaultIdMethod="native" package="OpenSondage.Database" namespace="OpenSondage\Database">
  <table name="poll" phpName="Poll">
    <column name="id" type="integer" required="true" primaryKey="true" autoIncrement="true"/>
    <column name="name" type="VARCHAR" size="255"  />
    
    <behavior name="query_cache" />
  </table>
</database>