Byte Buddy issue with PowerMock

ByteBuddyWithPowerMockTest.java

import net.bytebuddy.ByteBuddy;
import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;

import org.mockito.Mock;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.testng.PowerMockTestCase;
import org.testng.annotations.Test;

@PrepareForTest(ByteBuddyWithPowerMockTest.SampleClass.class)
public class ByteBuddyWithPowerMockTest extends PowerMockTestCase {

  public static class SampleClass { }

  @Mock
  private SampleClass sample;

  @Test
  public void test() throws InstantiationException, IllegalAccessException {
    System.out.println(sample);
    System.out.println(proxy(sample));
  }

  private static SampleClass proxy(SampleClass sample)
      throws IllegalAccessException, InstantiationException {
    return new ByteBuddy()
        .subclass(sample.getClass())
        .make()
        .load(sample.getClass().getClassLoader(), ClassLoadingStrategy.Default.WRAPPER)
        .getLoaded().newInstance();
  }
}

pom.xml

...
			<dependency>
				<groupId>org.powermock</groupId>
				<artifactId>powermock-module-testng</artifactId>
				<version>1.6.2</version>
			</dependency>
            <dependency>
                <groupId>org.powermock</groupId>
                <artifactId>powermock-api-mockito</artifactId>
                <version>1.6.2</version>
                <exclusions>
                    <exclusion>
                        <groupId>org.mockito</groupId>
                        <artifactId>mockito-all</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
            <dependency>
                <groupId>org.mockito</groupId>
                <artifactId>mockito-core</artifactId>
                <version>1.10.19</version>
            </dependency>
...

StackTrace

test/ByteBuddyWithPowerMockTest$SampleClass$$EnhancerByMockitoWithCGLIB$$86407ee5

	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
	at net.bytebuddy.dynamic.loading.ByteArrayClassLoader.access$300(ByteArrayClassLoader.java:19)
	at net.bytebuddy.dynamic.loading.ByteArrayClassLoader$ClassLoadingAction.run(ByteArrayClassLoader.java:420)
	at net.bytebuddy.dynamic.loading.ByteArrayClassLoader$ClassLoadingAction.run(ByteArrayClassLoader.java:375)
	at java.security.AccessController.doPrivileged(Native Method)
	at net.bytebuddy.dynamic.loading.ByteArrayClassLoader.findClass(ByteArrayClassLoader.java:131)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at net.bytebuddy.dynamic.loading.ByteArrayClassLoader.load(ByteArrayClassLoader.java:120)
	at net.bytebuddy.dynamic.loading.ClassLoadingStrategy$Default$WrappingDispatcher.load(ClassLoadingStrategy.java:265)
	at net.bytebuddy.dynamic.loading.ClassLoadingStrategy$Default.load(ClassLoadingStrategy.java:107)
	at net.bytebuddy.dynamic.DynamicType$Default$Unloaded.load(DynamicType.java:3179)
	at test.ByteBuddyWithPowerMockTest.proxy(ByteBuddyWithPowerMockTest.java:30)
	at test.ByteBuddyWithPowerMockTest.test(ByteBuddyWithPowerMockTest.java:22)
	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:497)
	at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:85)
	at org.testng.internal.Invoker.invokeMethod(Invoker.java:659)
	at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:845)
	at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1153)
	at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
	at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:108)
	at org.testng.TestRunner.privateRun(TestRunner.java:771)
	at org.testng.TestRunner.run(TestRunner.java:621)
	at org.testng.SuiteRunner.runTest(SuiteRunner.java:357)
	at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:352)
	at org.testng.SuiteRunner.privateRun(SuiteRunner.java:310)
	at org.testng.SuiteRunner.run(SuiteRunner.java:259)
	at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
	at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
	at org.testng.TestNG.runSuitesSequentially(TestNG.java:1199)
	at org.testng.TestNG.runSuitesLocally(TestNG.java:1124)
	at org.testng.TestNG.run(TestNG.java:1032)
	at org.testng.IDEARemoteTestNG.run(IDEARemoteTestNG.java:72)
	at org.testng.RemoteTestNGStarter.main(RemoteTestNGStarter.java:122)
	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:497)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: java.lang.ClassNotFoundException: test.ByteBuddyWithPowerMockTest$SampleClass$$EnhancerByMockitoWithCGLIB$$86407ee5
	at net.bytebuddy.dynamic.loading.ByteArrayClassLoader$ClassLoadingAction.run(ByteArrayClassLoader.java:422)
	at net.bytebuddy.dynamic.loading.ByteArrayClassLoader$ClassLoadingAction.run(ByteArrayClassLoader.java:375)
	at java.security.AccessController.doPrivileged(Native Method)
	at net.bytebuddy.dynamic.loading.ByteArrayClassLoader.findClass(ByteArrayClassLoader.java:131)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 43 more

I am currently on vacation, but I will look at it first time I am back. First suspicion: Byte Buddy is not currently configured to keep a reference to the generated class'es byte code after it is first loaded. Try the manifest version of the wrapper strategy. I guess, power mock requires explicit access to the byte code!