Maven GAE Plugin

I wrote on S.O.: http://stackoverflow.com/questions/9428048/maven-gae-plugin-using-google-cloud-sql

Good morning,

I am trying to local test my web application, which makes use of:

Spring (core + MVC)
Google AppEngine
Google Cloud SQL
Hibernate
In this page https://developers.google.com/cloud-sql/docs/developers_guide_java
Google explains how to make the hello world run, and that's right. I
deploy to AppEngine with no problems.

The next need is testing on the local system, with a local standard
mysql instance and that document goes ahead in the explanation. You
can give your local access credentials by command-line or by Google
Eclipse Plugin.

But I am using the Maven GAE Plugin http://www.kindleit.net/maven_gae_plugin/
and simple mvn gae:run ends up with this error:

Cannot resolve reference to bean 'mySessionFactory' while setting bean
property 'sessionFactory'; nested exception is
org.springframework.beans.factory.BeanCreationException: Error
creating bean with name 'mySessionFactory' defined in ServletContext
resource [/WEB-INF/spring/root-context.xml]: Invocation of init method
failed; nested exception is java.lang.IllegalStateException: System
property rdbms.driver must be set.:
java.lang.IllegalStateException: System property rdbms.driver must be
set.
at
com.google.appengine.api.rdbms.dev.LocalRdbmsServiceLocalDriver.registerDriver(LocalRdbmsServiceLocalDriver.java:
80)

That's a pretty descriptive error, so I desperately tried:

mvn gae:run -Drdbms.server=local -Drdbms.driver=com.mysql.jdbc.Driver -
Drdbms.url=jdbc:mysql://localhost:3306/prova?user=root&password=pass

... with no result! :-(

Help! O.O