Powermock, failed to transform class - mockito

Question

I am using Powermock with Spock. Code I am testing is Java. Using it to mock a static method.
testCompile group: 'org.mockito', name: 'mockito-core', version: '2.8.9'
testCompile group: 'org.powermock', name: 'powermock-api-mockito2', version: '2.0.2'
testCompile group: 'org.powermock', name: 'powermock-module-junit4', version: '2.0.2'
testCompile group: 'org.powermock', name: 'powermock-module-junit4-rule-agent', version: '2.0.2'
I am unit testing class called: Serializer.
I am mocking a method getInstance() in MySingleton.
#RunWith(PowerMockRunner.class)
#PrepareForTest(MySingleton.class)
class SerializerSpec extends BaseSpecification {
#Rule
PowerMockRule mPowerMockRule = new PowerMockRule();
def "some test"() {
// ...
}
}
I get:
java.lang.RuntimeException: java.lang.IllegalStateException: Failed to transform class with name com.MySingleton. Reason: cannot find org.reflections.util.FilterBuilder$Include
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.getTestMethods(PowerMockJUnit44RunnerDelegateImpl.java:105)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.<init>(PowerMockJUnit44RunnerDelegateImpl.java:85)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl.<init>(PowerMockJUnit47RunnerDelegateImpl.java:42)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit49RunnerDelegateImpl.<init>(PowerMockJUnit49RunnerDelegateImpl.java:25)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.createDelegatorFromClassloader(JUnit4TestSuiteChunkerImpl.java:165)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.createDelegatorFromClassloader(JUnit4TestSuiteChunkerImpl.java:47)
at org.powermock.tests.utils.impl.AbstractTestSuiteChunkerImpl.createTestDelegators(AbstractTestSuiteChunkerImpl.java:107)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.<init>(JUnit4TestSuiteChunkerImpl.java:69)
at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.<init>(AbstractCommonPowerMockRunner.java:36)
at org.powermock.modules.junit4.PowerMockRunner.<init>(PowerMockRunner.java:34)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:104)
at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:86)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:33)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createUnfilteredTest(JUnit4TestLoader.java:84)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createTest(JUnit4TestLoader.java:70)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.loadTests(JUnit4TestLoader.java:43)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:444)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: java.lang.IllegalStateException: Failed to transform class with name com.MySingleton. Reason: cannot find org.reflections.util.FilterBuilder$Include
at org.powermock.core.classloader.javassist.JavassistMockClassLoader.defineAndTransformClass(JavassistMockClassLoader.java:119)
at org.powermock.core.classloader.MockClassLoader.loadMockClass(MockClassLoader.java:174)
at org.powermock.core.classloader.MockClassLoader.loadClassByThisClassLoader(MockClassLoader.java:102)
at org.powermock.core.classloader.DeferSupportingClassLoader.loadClass1(DeferSupportingClassLoader.java:147)
at org.powermock.core.classloader.DeferSupportingClassLoader.loadClass(DeferSupportingClassLoader.java:98)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at sun.reflect.generics.factory.CoreReflectionFactory.makeNamedType(CoreReflectionFactory.java:114)
at sun.reflect.generics.visitor.Reifier.visitClassTypeSignature(Reifier.java:125)
at sun.reflect.generics.tree.ClassTypeSignature.accept(ClassTypeSignature.java:49)
at sun.reflect.annotation.AnnotationParser.parseSig(AnnotationParser.java:439)
at sun.reflect.annotation.AnnotationParser.parseClassValue(AnnotationParser.java:420)
at sun.reflect.annotation.AnnotationParser.parseClassArray(AnnotationParser.java:724)
at sun.reflect.annotation.AnnotationParser.parseArray(AnnotationParser.java:531)
at sun.reflect.annotation.AnnotationParser.parseMemberValue(AnnotationParser.java:355)
at sun.reflect.annotation.AnnotationParser.parseAnnotation2(AnnotationParser.java:286)
at sun.reflect.annotation.AnnotationParser.parseAnnotations2(AnnotationParser.java:120)
at sun.reflect.annotation.AnnotationParser.parseAnnotations(AnnotationParser.java:72)
at java.lang.Class.createAnnotationData(Class.java:3521)
at java.lang.Class.annotationData(Class.java:3510)
at java.lang.Class.getAnnotation(Class.java:3415)
at org.junit.internal.MethodSorter.getDeclaredMethods(MethodSorter.java:52)
at org.junit.internal.runners.TestClass.getAnnotatedMethods(TestClass.java:45)
at org.junit.internal.runners.TestClass.getTestMethods(TestClass.java:31)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.powermock.reflect.internal.WhiteboxImpl.performMethodInvocation(WhiteboxImpl.java:1854)
at org.powermock.reflect.internal.WhiteboxImpl.doInvokeMethod(WhiteboxImpl.java:816)
at org.powermock.reflect.internal.WhiteboxImpl.invokeMethod(WhiteboxImpl.java:681)
at org.powermock.reflect.Whitebox.invokeMethod(Whitebox.java:401)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.getTestMethods(PowerMockJUnit44RunnerDelegateImpl.java:103)
... 30 more
Caused by: javassist.CannotCompileException: cannot find org.reflections.util.FilterBuilder$Include
at javassist.expr.NewExpr.replace(NewExpr.java:236)
at org.powermock.core.transformers.javassist.support.PowerMockExpressionEditor.edit(PowerMockExpressionEditor.java:73)
at javassist.expr.ExprEditor.loopBody(ExprEditor.java:217)
at javassist.expr.ExprEditor.doit(ExprEditor.java:96)
at javassist.CtClassType.instrument(CtClassType.java:1541)
at org.powermock.core.transformers.javassist.InstrumentMockTransformer.transform(InstrumentMockTransformer.java:41)
at org.powermock.core.transformers.javassist.AbstractJavaAssistMockTransformer.transform(AbstractJavaAssistMockTransformer.java:40)
at org.powermock.core.transformers.support.DefaultMockTransformerChain.transform(DefaultMockTransformerChain.java:43)
at org.powermock.core.classloader.MockClassLoader.transformClass(MockClassLoader.java:184)
at org.powermock.core.classloader.javassist.JavassistMockClassLoader.defineAndTransformClass(JavassistMockClassLoader.java:102)
... 63 more
Caused by: javassist.NotFoundException: org.reflections.util.FilterBuilder$Include
at javassist.ClassPool.get(ClassPool.java:422)
at javassist.expr.NewExpr.replace(NewExpr.java:210)
... 72 more