Error when doing "mvn gae:run" using Spring Roo on Google App Engine with GWT

1. save the following script to a file:

project --topLevelPackage com.my.gae --projectName gaetest --java 6
persistence setup --provider DATANUCLEUS --database GOOGLE_APP_ENGINE
entity jpa --class ~.domain.Person
field string --fieldName name
web gwt setup
web gwt all --proxyPackage ~.proxy --requestPackage ~.request
web gwt gae update
logging setup --level DEBUG

2. roo script --file <path-to-above-script>
This will give an error which is fixed in the next step

3. Fix a bug in the pom by adding <scope>runtime</scope> to the datanucleus-core dependency

<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-core</artifactId>
<version>3.0.7</version>
<scope>runtime</scope>
</dependency>

4. Edit the ApplicationScaffold.gwt.xml file and removing the path to these lines as follows:

<source path="request"/>
<source path="proxy"/>

Now the app will build. Without this change, the app will not build.

5. mvn gae:run

The following error will result:

SEVERE: One or more exceptions caught, see full set in UmbrellaException#getCauses
java.lang.Throwable: One or more exceptions caught, see full set in UmbrellaException#getCauses
at Unknown.RuntimeException_1()
at Unknown.UmbrellaException_1()
at Unknown.$processPayload()
at Unknown.$onTransportSuccess()
at Unknown.$onTransportSuccess_0()
at Unknown.$onResponseReceived()
2012-04-05 00:13:31,311 [[email protected]] DEBUG org.springframework.orm.jpa.support.OpenEntityManagerInViewF
ilter - Closing JPA EntityManager in OpenEntityManagerInViewFilter
at Unknown.$onResponseReceived_0()
2012-04-05 00:13:31,312 [[email protected]] DEBUG org.springframework.orm.jpa.EntityManagerFactoryUtils - Clos
ing JPA EntityManager
Caused by: java.lang.Throwable: Server Error: No results for query: SELECT COUNT(o) FROM Person o
at Unknown.Exception_0()
at Unknown.RuntimeException_0()
at Unknown.$onFailure()
at Unknown.onFailure()
at Unknown.$onFail()
at Unknown.$processPayload()
at Unknown.$onTransportSuccess()