Duplicate parameter error while trying to use pattern bound variables or globals in accumulate function

Whenever I attempt to reference a pattern bound variable (declared outside of accumulate) or a global from within an accumulate function, I get a "Duplicate parameter" error.

Example of pattern bound variable:

rule "Test"
when
$obj: SomeObject()
Integer() from accumulate( AnotherObject() , init (int total = 0 ), action ( total += $obj.getValue(); ), reverse ( total -= $obj.getValue(); ), result ( total) )
then
System.out.println("HI!");
end

The same happens when if I attempt to use a global. Here is an exact stacktrace of the error:
org.drools.rule.InvalidRulePackage: Rule Compilation error : [Rule
name=Daily Core Hours, agendaGroup=MAIN, salience=0, no-loop=false]
com/kronos/webta/service/smarttime/rules/Rule_Daily_Core_Hours_0.java
(32:1301) : Duplicate parameter $schedOut
com/kronos/webta/service/smarttime/rules/Rule_Daily_Core_Hours_0.java
(32:1330) : Duplicate parameter $schedIn
com/kronos/webta/service/smarttime/rules/Rule_Daily_Core_Hours_0.java
(41:1735) : Duplicate parameter $schedOut
com/kronos/webta/service/smarttime/rules/Rule_Daily_Core_Hours_0.java
(41:1764) : Duplicate parameter $schedIn
com/kronos/webta/service/smarttime/rules/Rule_Daily_Core_Hours_0.java
(51:2330) : Duplicate parameter $schedOut
com/kronos/webta/service/smarttime/rules/Rule_Daily_Core_Hours_0.java
(51:2359) : Duplicate parameter $schedIn
com/kronos/webta/service/smarttime/rules/Rule_Daily_Core_Hours_0.java
(58:2738) : Duplicate parameter $schedOut
com/kronos/webta/service/smarttime/rules/Rule_Daily_Core_Hours_0.java
(58:2767) : Duplicate parameter $schedIn

at org.drools.rule.Package.checkValidity(Package.java:424)
at
org.drools.common.AbstractRuleBase.addPackage(AbstractRuleBase.java:364)
at
com.kronos.webta.service.smarttime.rules.maxiflex.FlowTest.setUpBeforeClass(FlowTest.java:79)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at
org.junit.internal.runners.ClassRoadie.runBefores(ClassRoadie.java:49)
at
org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:36)
at
org.junit.internal.runners.JUnit4ClassRunner.run(JUnit4ClassRunner.java:42)
at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:38)
at
org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)