When using proguard with your Android project, you may face the following proguard error:
Proguard returned with error code 1. See console Unexpected error while evaluating instruction: Class = [org/jsoup/parser/TreeBuilder] Method = [insertInFosterParent(Lorg/jsoup/nodes/Node;)V] Instruction = [70] aload_2 v2 Exception = (null) Unexpected error while performing partial evaluation: Class = [org/jsoup/parser/TreeBuilder] Method = [insertInFosterParent(Lorg/jsoup/nodes/Node;)V] Exception = (null) java.lang.NullPointerException at proguard.evaluation.Variables.aload(Variables.java:264) at proguard.evaluation.Processor.visitVariableInstruction(Processor.java:677) at proguard.classfile.instruction.VariableInstruction.accept(VariableInstruction.java:306) at proguard.optimize.evaluation.PartialEvaluator.evaluateSingleInstructionBlock(PartialEvaluator.java:729) at proguard.optimize.evaluation.PartialEvaluator.evaluateInstructionBlock(PartialEvaluator.java:575) at proguard.optimize.evaluation.PartialEvaluator.evaluateInstructionBlockAndExceptionHandlers(PartialEvaluator.java:533) at proguard.optimize.evaluation.PartialEvaluator.visitCodeAttribute0(PartialEvaluator.java:221) at proguard.optimize.evaluation.PartialEvaluator.visitCodeAttribute(PartialEvaluator.java:180) at proguard.optimize.evaluation.LivenessAnalyzer.visitCodeAttribute(LivenessAnalyzer.java:195) at proguard.optimize.evaluation.VariableOptimizer.visitCodeAttribute(VariableOptimizer.java:102) at proguard.classfile.attribute.CodeAttribute.accept(CodeAttribute.java:101) at proguard.classfile.ProgramMethod.attributesAccept(ProgramMethod.java:79) at proguard.classfile.attribute.visitor.AllAttributeVisitor.visitProgramMember(AllAttributeVisitor.java:95) at proguard.classfile.util.SimplifiedVisitor.visitProgramMethod(SimplifiedVisitor.java:91) at proguard.classfile.ProgramMethod.accept(ProgramMethod.java:71) at proguard.classfile.ProgramClass.methodsAccept(ProgramClass.java:439) at proguard.classfile.visitor.AllMethodVisitor.visitProgramClass(AllMethodVisitor.java:47) at proguard.classfile.ProgramClass.accept(ProgramClass.java:281) at proguard.classfile.ClassPool.classesAccept(ClassPool.java:114) at proguard.optimize.Optimizer.execute(Optimizer.java:764) at proguard.ProGuard.optimize(ProGuard.java:325) at proguard.ProGuard.execute(ProGuard.java:114) at proguard.ProGuard.main(ProGuard.java:499)
Fortunately, this error has been fixed at the latest proguard release (4.7), but the Android SDK still uses a previous version.
So all you have to do, it to download the latest proguard version from here, unzip it and copy paste the 3 jars from the “lib” folder to your Android-SDK folder at ANDROID_SDK_HOME/tools/proguard/lib and replace the old jars.
Backing up is always a smart and proper move.