I did manage to build it (master and feature branches both) but I had to download latest Gradle (4.6) and use Java 9.

Looking at your uber jar:

• You are missing the classes your uber jar, hence the CNFE
  • I checked some of those CNFE classes, such as org.apache.ivy.core.report.ResolveReport or even javax.servlet.http.HttpServlet
  • You packaging is hence wrong and you either need to fix the uber jar, or run java command and add missing libs on classpath/module-path
• Many entries inside that uber jar are duplicated
  • property files, beans xsd files, module-info even...
  • You may want to clear this up before going any further