mock-maker-inline - Could not initialize inline Byte Buddy mock maker (power-mockito + jdk 8 + bytebuddy)

Question

I am using Powermockito to mock and spy static classes. Version: 2.0.4

Also using mockito-core version 3.0.0. In, one of my projects, i am able to mockStatic by enabling mock-maker-inline as specified here https://github.com/powermock/powermock-examples-maven/blob/master/mockito2/src/test/resources/org/powermock/extensions/configuration.properties

But, when i tried the same approach on my another project, facing the following error:

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.ghx.tpm.api.ISubscribedProductParameterService]: Factory method 'subscribedProductParameterService' threw exception; nested exception is java.lang.IllegalStateException: Could not initialize plugin: interface org.mockito.plugins.MockMaker (alternate: null)
Caused by: java.lang.IllegalStateException: Could not initialize plugin: interface org.mockito.plugins.MockMaker (alternate: null)
Caused by: java.lang.IllegalStateException: Failed to load interface org.mockito.plugins.MockMaker implementation declared in sun.misc.CompoundEnumeration@614aeccc
Caused by: java.lang.IllegalStateException: Failed to load MockMaker implementation: mock-maker-inline
Caused by: java.lang.IllegalStateException: Internal problem occurred, please report it. Mockito is unable to load the default implementation of class that is a part of Mockito distribution. Failed to load interface org.mockito.plugins.MockMaker
Caused by: org.mockito.exceptions.base.MockitoInitializationException: 

Could not initialize inline Byte Buddy mock maker. (This mock maker is not supported on Android.)

Java               : 1.8
JVM vendor name    : Oracle Corporation
JVM vendor version : 25.161-b12
JVM name           : Java HotSpot(TM) 64-Bit Server VM
JVM version        : 1.8.0_161-b12
JVM info           : mixed mode
OS name            : Linux
OS version         : 4.4.0-166-generic

Caused by: java.lang.IllegalStateException: Error during attachment using: net.bytebuddy.agent.ByteBuddyAgent$AttachmentProvider$Compound@3c89bb12
Caused by: java.lang.reflect.InvocationTargetException
Caused by: java.lang.NullPointerException 

Can you please help in resolving this issue?

Additional details:

• I am mocking static spy class here.
• byte-buddy jar resolved dependency version is 1.9.10
• will overlap of mockito2 and powermock-api-mockito2 will cause issue in loading MockMaker? how to resolve them?
• If the test is executed in IDE it is working fine. but fails when run in maven console.

Additional findings: Ensured JavassistMockClassLoader is used by adding @PrepareForTest and PowerMockRunner (since one of my other project worked with same configuration)

Facing Null pointer Exception exactly at this line:

ByteBuddyAgent.java (private static void install(AttachmentProvider attachmentProvider, String processId, String argument, AgentProvider agentProvider)
 Attacher.install(attachmentAccessor.getVirtualMachineType(), processId, agentProvider.resolve().getAbsolutePath(), argument);

Classloader while it is failing is - AppLaunchClassLoader. ( Whereas for working project it is URLClassLoader). Not sure if this difference could be a reason.

Update 2:

• @PowerMockRule --> This Anntoation initializes JVM agent once
• During Mockito.mock invocation, it tries to load mock-maker-inline, which inturn loads Agent into JVM. Will this cause any issue? I believe, VirtualMachine.attach() method is invoked twice. Not sure if it will cause any problem.

Eclipse IDE loads mock-maker-inline via tools.jar (working fine in IDE) Maven command line loads mock-maker-inline via powermock-module-javaagent (failing with initialization error).- Any suggestions to force maven console to pick up mock-maker-inline initialization using tools.jar?

Update 3: I went to a minimalistic approach. Removed all Spring runners, Bean creations, Context Configurations. Just kept a plain PowerMockRunner + static mock on UUID.randomUUID() + Sysout.

Still facing mock-maker-inline initialization error. feeling very wierd!! same configuration works on my other project in same workspace!

Answer 1

Found the issue. @PowerMockRule (which utilizes powermock-modules-javaagent.JAR) is the culprit.

Using @PowerMockRule along with mock-maker-inline causing this issue.

I have to Replace PowerMockRule with @RunsWith(PowerMockRunner.class) to fix this. Thanks.

Update 1: after above fix, facing issues with classloader as discussed here https://github.com/raphw/byte-buddy/issues/813. Please feel free to share your suggestions. Thanks

Answer 2

Be sure to choose a JDK, not "jre".

Look into the file Path to see if it is jdk or jre.

Could not initialize plugin: interface org.mockito.plugins.MockMaker

Could not initialize inline Byte Buddy mock maker. (This mock maker is not supported on Android.)