title: ERROR:The type org.apache.log4j.Logger cannot be resolved. It is indirectly referenced from required .class files
body: <p>Trying to upgrade a project from using Camel v2.21.2 to using Camel v2.22.0</p>
  
  <p>This entails going from Spring v4.x to v5.x and from Spring-boot v1.5.x to Spring-boot v2.0.4.RELEASE.</p>
  
  <p>Project uses groovy-all 2.4.15. We are not using log4j in our project, we are  using slf4j-api(1.7.25) and logback(1.2.3) in our project. Yet, running a Maven install is giving an error saying that some class is using log4j</p>
  
  <p>When I added log4j(1.2.17) dependency it is working fine but we don't want to add it.   </p>
  
  <p>Is there something that can be excluded from the spring-boot starter? Any other solutions? Any hints on how to diagnose the problem?</p>