ParseExpressionErrorResult.getLines() (and other error results classes other than CompilationProblemErrorResult) returns an empty array. So error message tells that the error line is -1. (e.g. JBRULESTest.testJBRULES2872())

Message [id=1, kieBase=defaultKieBase, level=ERROR, path=rules1.drl, line=-1, column=0
   text=Unable to Analyse Expression enumVal == TestEnum.ONE || enumVal == TestEnum.TWO:]

https://github.com/kiegroup/drools/blob/master/drools-model/drools-model-compiler/src/main/java/org/drools/modelcompiler/builder/errors/ParseExpressionErrorResult.java#L44-L46

Looking at PatternDSL.findAllConstraint(), BaseDescr (constraint) retains its line number but ConstraintExpression (constraintExpression) doesn't. So we cannot find the line number inside
ConstraintParser.drlxParse().

https://github.com/kiegroup/drools/blob/master/drools-model/drools-model-compiler/src/main/java/org/drools/modelcompiler/builder/generator/visitor/pattern/PatternDSL.java#L134-L136