There are two core projects (org.openjdk.jmc.flightrecorder.writer, org.openjdk.jmc.jdp) that lacks resources, and therefore do not have a resources folder. It seems a common way to handle this (that makes diverse combinations of tools and IDEs happy, e.g. the maven tooling in Eclipse) is to add an empty .gitignore file to these folders and exclude them from the build properties.