attempted duplicate class definition

[Keir Lawson]

Hello,

I'm getting a slightly odd problem when trying to run a suite of Spock (0.7) tests.  One of my tests is failing with the error below

org.springframework.cglib.core.CodeGenerationException: java.lang.reflect.InvocationTargetException-->null
    at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:237)
    at org.springframework.cglib.reflect.FastClass$Generator.create(FastClass.java:64)
    at org.springframework.cglib.proxy.MethodProxy.helper(MethodProxy.java:121)
    at org.springframework.cglib.proxy.MethodProxy.init(MethodProxy.java:74)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:202)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:713)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:646)
    at my.project.MyServiceSpec.get list of request types(MyServiceSpec.groovy:40)
Caused by: java.lang.reflect.InvocationTargetException
    at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:384)
    at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:219)
    ... 12 more
Caused by: java.lang.LinkageError: loader (instance of  sun/misc/Launcher$AppClassLoader): attempted  duplicate class definition for name: "my/project/service/MyService$$FastClassByCGLIB$$747581e9"
    ... 14 more

However when I run this test in isolation or as the first test or several it passes just fine, anyone have any idea what the issue could be?

Thanks

Keir