When I importing the projects into Eclipse (gson, commons-cli), I see many errors. I have convert them to Maven projects. I can provide more details, please ask. The most frequent error is "cannot be resolve to a type". The projects are old and I'm using Java 16.0.2, I suspect something with that fact.
Some of errors including "The type javax.lang.model.element.PackageElement is not accessible" and "maven-remote-resources-plugin (goal "process") is ignored by m2e.
- Plugin execution not covered by lifecycle configuration: org.apache.maven.plugins:maven-antrun-plugin:3.0.0:run (execution: javadoc.resources, phase: generate-sources)"
Any idea ?