Building Jenkins in Eclipse

[Mario Jauvin]

I followed the instructions in https://github.com/jenkinsci/jenkins/blob/master/CONTRIBUTING.md and when I import the maven jenkins-parent project into eclipse 2018-12 or springtools4 I get a compilation error in Jenkins-core as follows:

Type mismatch: cannot convert from CopyOnWriteArrayList<ExtensionComponent<Descriptor>> to CopyOnWriteArrayList<ExtensionComponent<Descriptor<T>>> in DescriptorExtensionList.java.

Does anyone know why? I don't get it when I package or install using maven. I am totally flabbergasted  Of course I googled it to my heart's content and found 1 post but no one ever answered it.