[antlr-interest] error(10): internal error: org.antlr.analysis.NFAToDFAConverter.getPredicatesPerNonDeterministicAlt(NFAToDFAConverter.java:1604): no AST/token for nonepsilon target w/o predicate

[Nat Wyatt]

We are intermittently getting the error in the subject line running 
ANTLR 3.1.1. It happens only in our build system, and not every time. 
Multithreaded NFA conversion is off (by default we do not specify 
--Xmultithreaded).

Since it is not easily reproducible, I was wondering if anyone had hints 
for what to look for.

As far as I can tell the problem has not been mentioned on the 
antlr-interest list and there's no issue for it on github.

Thanks,

nat