[wildfly-dev] jdk 9 reflection problem

We have just upgraded our jdk build to 9-ea+149 which has tightened up the accessibility rules. The recommendation seems to be to use the --add-opens flag to override the rules. I tried export MAVEN_OPTS="--add-opens java.base/java.util=ALL-UNNAMED" which made no difference. Our jdk 9 FAQ does not provided any hints either. Can anyone provide advice on how to resolve the following maven build error: [WARNING] Error injecting: org.apache.maven.plugins.war.WarMojo com.google.inject.ProvisionException: Unable to provision, see the following errors: 1) Error injecting constructor, java.lang.ExceptionInInitializerError at org.apache.maven.plugins.war.WarMojo.<init>(Unknown Source) while locating org.apache.maven.plugins.war.WarMojo ... Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make field private final java.util.Comparator java.util.TreeMap.comparator accessible: module java.base does not "opens java.util" to unnamed m odule @669f2128 at java.base/jdk.internal.reflect.Reflection.throwInaccessibleObjectException(Reflection.java:427) at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:201) at java.base/java.lang.reflect.Field.checkCanSetAccessible(Field.java:171) at java.base/java.lang.reflect.Field.setAccessible(Field.java:165) at com.thoughtworks.xstream.core.util.Fields.locate(Fields.java:40) at com.thoughtworks.xstream.converters.collections.TreeMapConverter.<clinit>(TreeMapConverter.java:50) -- Michael Musgrove Transactions Team e: mmusgrov(a)redhat.com t: +44 191 243 0870 Our mission:To be the catalyst in communities of customers, contributors, and partners creating better technology the open source way. Registered in England and Wales under Company Registration No. 03798903 Directors: Michael Cunningham (US), Paul Hickey (Ireland), Matt Parson (US), Charles Peters (US) Michael Cunningham (US), Charles Peters (US), Matt Parson (US), Michael O'Neill(Ireland)