[에러] Requested bean is currently in creation: Is there an unresolvable circular reference?

에러 메시지

through method 'setCallServiceV1' parameter 0: Error creating bean with name 'callServiceV1': Requested bean is currently in creation: Is there an unresolvable circular reference?

원인

스프링부트 2.6부터 순환참조 기본적으로 금지하도록 정책이 변경됨

해결책

## application.properties에 넣어주자.
spring.main.allow-circular-references=true