Having a test case like this , it sometimes fails on
java.lang.RuntimeException: java.util.concurrent.ExecutionException: [Error: unable to resolve method using strict-mode: org.drools.compiler.integrationtests.facts.FactWithEnum.AnEnum()]
... see here . When using direct imports that are commented out in the pasted example, I see very rarely also a ClassCastException. See stacktrace here .
Tested with mvel 2.2.8 on 6.5.x branch, 2.3.0 and 2.3.1 on master branch.