gistfile1.txt

grails11577 $ java -version
java version "1.8.0-ea"
Java(TM) SE Runtime Environment (build 1.8.0-ea-b106)
Java HotSpot(TM) 64-Bit Server VM (build 25.0-b48, mixed mode)
grails11577 $ 
grails11577 $ cat application.properties 
#Grails Metadata file
#Fri Jul 11 14:22:05 CDT 2014
app.grails.version=2.4.2
app.name=grails11577
app.version=0.1
grails11577 $ 
grails11577 $ cat grails-app/domain/grails11577/Account.groovy 
package grails11577

class Account {

    static constraints = {
    }
}
grails11577 $ 
grails11577 $ cat src/groovy/grails11577/MyHelper.groovy 
package grails11577

@grails.compiler.GrailsTypeChecked
class MyHelper {

    def someMethod() {
        Account.withSession {}
        Account.withNewSession {}
    }
}
grails11577 $ 
grails11577 $ rm -rf target/classes/grails11577/
grails11577 $ grails compile
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=512m; support was removed in 8.0
| Compiling 2 source files.