Starting from v7.37 onwards, the OptaPlanner examples project wouldn't build with Maven even though the full project would. The error message is:

[ERROR]Failed to execute goal net.revelc.code.formatter:formatter-maven-plugin:2.11.0:format (default) on project optaplanner-examples: cannot find config file [[my local optaplanner-examples directory]:optaplanner-distribution-7.37.0.Final\examples\sources/../ide-configuration/eclipse-format.xml]

Copying the ide-configuration directory and files from the full project into the optaplanner-distribution-7.xx.0.Final\examples\ directory solved the problem. Maybe this could be included in future releases, and patched in the 7.37 - 7.41 versions?