[apex] Exception applying rule UnusedLocalVariable on trigger

[ankushsomani09]

Executed by : ant
Apex language : trigger code
Rule name: UnusedLocalVariable subset of

<rule ref="category/apex/bestpractices.xml" />

code:
trigger leadOwnerUpdate on Lead (after update) { for(Lead Id : Trigger.new) {} }

Error:

Exception applying rule UnusedLocalVariable on file E:\writable\OneDrive\OneDrive - ANkush\Documents\sfdc\src\triggers\leadOwnerUpdate.trigger, continuing with next rule
java.lang.NullPointerException
        at net.sourceforge.pmd.lang.apex.rule.bestpractices.UnusedLocalVariableRule.visit(UnusedLocalVariableRule.java:31)
        at net.sourceforge.pmd.lang.apex.ast.ASTVariableDeclaration.jjtAccept(ASTVariableDeclaration.java:22)
        at net.sourceforge.pmd.lang.apex.rule.ApexRuleChainVisitor.visit(ApexRuleChainVisitor.java:42)
        at net.sourceforge.pmd.lang.rule.AbstractRuleChainVisitor.visitAll(AbstractRuleChainVisitor.java:96)
        at net.sourceforge.pmd.RuleChain.apply(RuleChain.java:67)
        at net.sourceforge.pmd.RuleSets.apply(RuleSets.java:140)
        at net.sourceforge.pmd.SourceCodeProcessor.processSource(SourceCodeProcessor.java:194)
        at net.sourceforge.pmd.SourceCodeProcessor.processSourceCodeWithoutCache(SourceCodeProcessor.java:107)
        at net.sourceforge.pmd.SourceCodeProcessor.processSourceCode(SourceCodeProcessor.java:89)
        at net.sourceforge.pmd.SourceCodeProcessor.processSourceCode(SourceCodeProcessor.java:51)
        at net.sourceforge.pmd.processor.PmdRunnable.call(PmdRunnable.java:78)
        at net.sourceforge.pmd.processor.MonoThreadProcessor.runAnalysis(MonoThreadProcessor.java:29)
        at net.sourceforge.pmd.processor.AbstractPMDProcessor.processFiles(AbstractPMDProcessor.java:122)
        at net.sourceforge.pmd.PMD.processFiles(PMD.java:310)
        at net.sourceforge.pmd.ant.internal.PMDTaskImpl.doTask(PMDTaskImpl.java:196)
        at net.sourceforge.pmd.ant.internal.PMDTaskImpl.execute(PMDTaskImpl.java:281)
        at net.sourceforge.pmd.ant.PMDTask.execute(PMDTask.java:50)
        at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:293)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
        at org.apache.tools.ant.Task.perform(Task.java:352)
        at org.apache.tools.ant.Target.execute(Target.java:437)
        at org.apache.tools.ant.Target.performTasks(Target.java:458)
        at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1406)
        at org.apache.tools.ant.Project.executeTarget(Project.java:1377)
        at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
        at org.apache.tools.ant.Project.executeTargets(Project.java:1261)
        at org.apache.tools.ant.Main.runBuild(Main.java:857)
        at org.apache.tools.ant.Main.startAnt(Main.java:236)
        at org.apache.tools.ant.launch.Launcher.run(Launcher.java:287)
        at org.apache.tools.ant.launch.Launcher.main(Launcher.java:112)