mvn jetty:run fails on 5.2.3

[sebb]

Java8
cd app
mvn jetty:run
...
[WARNING] Failed startup of context
o.e.j.m.p.JettyWebAppContext@55fdf7f9{/roller,[file:/Users/sebb/Downloads/roller-weblogger-5.2.3-source/app/src/main/webapp/,
jar:file:/Users/sebb/.m2/repository/org/webjars/npm/angular/1.2.29/angular-1.2.29.jar!/META-INF/resources],STARTING}{file:/Users/sebb/Downloads/roller-weblogger-5.2.3-source/app/src/main/webapp/}
org.eclipse.jetty.util.MultiException: Multiple exceptions
    at org.eclipse.jetty.annotations.AnnotationConfiguration.scanForAnnotations
(AnnotationConfiguration.java:535)
...
[WARNING] !RequestLog
[INFO] Started ServerConnector@603cabc4{HTTP/1.1}{0.0.0.0:8080}
[INFO] Started @15807ms
[INFO] Started Jetty Server

http://localhost:8080/roller/
produces:

HTTP ERROR: 503
Problem accessing /roller/. Reason:
    Service Unavailable

Same issue with Java9