SpringBoot AOT-generated source fails to compile when Actuator is enabled on a WebFlux project

With the latest RC2 milestone of Spring Boot 3.0.0, compileAot task fails with the following errors:

> :compileAotJava
/Users/eme/Workspace/demo/build/generated/aotSources/org/springframework/boot/actuate/autoconfigure/endpoint/web/reactive/WebFluxEndpointManagementContextConfiguration__BeanDefinitions.java:72: error: ServerCodecConfigurerEndpointObjectMapperBeanPostProcessor has private access in WebFluxEndpointManagementContextConfiguration
  private static BeanInstanceSupplier<WebFluxEndpointManagementContextConfiguration.ServerCodecConfigurerEndpointObjectMapperBeanPostProcessor> getServerCodecConfigurerEndpointObjectMapperBeanPostProcessorInstanceSupplier(
                                                                                   ^
/Users/eme/Workspace/demo/build/generated/aotSources/org/springframework/boot/actuate/autoconfigure/endpoint/web/reactive/WebFluxEndpointManagementContextConfiguration__BeanDefinitions.java:74: error: ServerCodecConfigurerEndpointObjectMapperBeanPostProcessor has private access in WebFluxEndpointManagementContextConfiguration
    return BeanInstanceSupplier.<WebFluxEndpointManagementContextConfiguration.ServerCodecConfigurerEndpointObjectMapperBeanPostProcessor>forFactoryMethod(WebFluxEndpointManagementContextConfiguration.class, "serverCodecConfigurerEndpointObjectMapperBeanPostProcessor", EndpointObjectMapper.class);
                                                                              ^
/Users/eme/Workspace/demo/build/generated/aotSources/org/springframework/boot/actuate/autoconfigure/endpoint/web/reactive/WebFluxEndpointManagementContextConfiguration__BeanDefinitions.java:82: error: ServerCodecConfigurerEndpointObjectMapperBeanPostProcessor has private access in WebFluxEndpointManagementContextConfiguration
    Class<?> beanType = WebFluxEndpointManagementContextConfiguration.ServerCodecConfigurerEndpointObjectMapperBeanPostProcessor.class;
                                                                     ^
3 errors

With RC1, things worked properly. The attached replicator project was generated with the latest starter.spring.io. demo-regression-actuator-webflux.tgz

Comment From: bclozel

Probably related to #20291

Comment From: dr-eme

Also on RC1 (not able to test it on RC2 due to the above issue), there seems to be a missing hint on org.springframework.boot.actuate.data.mongo.MongoReactiveHealthIndicator.class when Spring Actuator is enabled with Spring Data MongoDB reactive.

Comment From: bclozel

@dr-eme could you create another issue for that? If you've got a complete stacktrace and a repro project, this will help a lot firguring out a fix.

Comment From: wilkinsona

It occurred to me that it should be possible to work around this on 3.0.0-RC2 by setting management.endpoints.jackson.isolated-object-mapper to false.