Adding module causes classloading issues

[Michael Hall]

JMX attach keeps telling me that RMI is not a accepted protocol.
I wondered if possibly this was a modular issue, I checked my main app jar…
jdeps halfpipe.jar
...
halfpipe.jar -> java.corba
…

which seems to say I need java.corba which I didn’t have.
If I add that with jlink I get…

java.lang.NoClassDefFoundError: javax/transaction/UserTransaction

from the quartz scheduler. This class should come from the included jta.jar, and usually does without the java.corba module.

This doesn’t appear to be included in any existing modules including corba. 
java -cp halfpipe.jar us.hall.cmdline.cmds.JRTLister /modules | grep javax.transaction
   /modules/java.sql/javax/transaction
    /modules/java.sql/javax/transaction/xa
     /modules/java.sql/javax/transaction/xa/XAException.class
     /modules/java.sql/javax/transaction/xa/XAResource.class
     /modules/java.sql/javax/transaction/xa/Xid.class
   /modules/java.transaction/javax/transaction
    /modules/java.transaction/javax/transaction/InvalidTransactionException.class
    /modules/java.transaction/javax/transaction/TransactionRequiredException.class
    /modules/java.transaction/javax/transaction/TransactionRolledbackException.class

So it doesn’t seem like it should be a ‘split package’ situation, unless possibly with java.transaction, not java.corba.
I’m not sure if ‘split package’ applies module to jar anyhow?

I’m still very new to this. Is there a command that would give me the module descriptor information for java.corba?
That might give me some idea why it is interfering with my jar classloading. 
Or any other suggestions as to why it might be doing this?