protobuf install failure on windows
<p>I tried to mvn install protobuf-v3.0.0 pre-built binaries on windows, but it prompts an error as below. </p>

<p>D:/Tools/protobuf-java-3.0.0/protobuf-3.0.0/java/core/src/main/java/com/google/protobuf/AbstractMessage.java:[327,26]</p>

<p>both com.google.protobuf.Message.Builder and com.google.protobuf.AbstractMessageLite.Builder define clone() method with different return type.</p>

<p>environments: jdk 1.6, maven 2.2.1</p>