NullPointerException thrown when ConfigurationClassEnhancer creates CGLIB proxy

[spencergibb]

Spring cloud uses boots dependency management of framework

[INFO] |     +- org.springframework:spring-context:jar:6.2.3-SNAPSHOT:compile

@sbrannen thinks it mightt be related to #34274

I can share links to CI builds if needed.

These are examples of failing tests https://github.com/spring-cloud/spring-cloud-stream/blob/fb3c889c9cbbbe0314824f401895118ae4b37a27/core/spring-cloud-stream-integration-tests/src/test/java/org/springframework/cloud/stream/binding/BindingServiceTests.java#L542-L557

java.lang.NullPointerException: Cannot read field "generatedClass" because "data" is null
	at org.springframework.cglib.proxy.Enhancer.nextInstance(Enhancer.java:783)
	at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:321)
	at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:562)
	at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:407)
	at org.springframework.context.annotation.ConfigurationClassEnhancer.createClass(ConfigurationClassEnhancer.java:169)
	at org.springframework.context.annotation.ConfigurationClassEnhancer.enhance(ConfigurationClassEnhancer.java:121)
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.enhanceConfigurationClasses(ConfigurationClassPostProcessor.java:539)
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanFactory(ConfigurationClassPostProcessor.java:311)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:363)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:153)
	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:791)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:609)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:752)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:439)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:318)
	at org.springframework.boot.builder.SpringApplicationBuilder.run(SpringApplicationBuilder.java:149)
	at org.springframework.cloud.stream.binding.BindingServiceTests.bindingAutostartup(BindingServiceTests.java:544)
	at java.base/java.lang.reflect.Method.invoke(Method.java:569)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

[wind57]

same in spring-cloud-kubernetes : https://github.com/spring-cloud/spring-cloud-kubernetes/actions/runs/13334222142/job/37245819905

[breun]

I found that for me changing @Configuration to @Configuration(proxyBeanMethods = false) worked as a workaround for this NullPointerException with Spring Framework 6.2.3 (Spring Boot 3.4.3).