记录一次奇诡 openFeign issue, 根本原因是 手动 @Import(FeignClientsConfiguration.class) 导致  Feign.Builder  实例类型一直错误

=== Fatal  Error:
@Import(FeignClientsConfiguration.class)
public class FeignBuilderUtils implements ApplicationContextAware {


=== Success:
//@Import(FeignClientsConfiguration.class)
public class FeignBuilderUtils implements ApplicationContextAware {


class FeignClientsConfiguration {
   ...

    @Configuration(proxyBeanMethods = false)
    @ConditionalOnClass(CircuitBreaker.class)
    @ConditionalOnProperty("feign.circuitbreaker.enabled")
    protected static class CircuitBreakerPresentFeignBuilderConfiguration {

    @Bean
    @Scope("prototype")
    @ConditionalOnMissingBean({ Feign.Builder.class, CircuitBreakerFactory.class })
    public Feign.Builder defaultFeignBuilder(Retryer retryer) {
      return Feign.builder().retryer(retryer);     <==  出错时进这里
    }

    @Bean
    @Scope("prototype")
    @ConditionalOnMissingBean
    @ConditionalOnBean(CircuitBreakerFactory.class)
    public Feign.Builder circuitBreakerFeignBuilder() {
      return FeignCircuitBreaker.builder();       <== 正常应该进这里
    }

    ...