Failed to execute goal

问题

I'm new to maven . I tired to mvn clean worked sucessfully but after mvn package I got the follwoing error

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3:compile (default-compile) on project L: Compilation failure: Compilation failure:
[ERROR] /home/user/L/src/main/java/edu/stanford/nlp/pipeline/NLP.java:[4,34] package edu.stanford.nlp.neural.rnn does not exist
[ERROR] 
[ERROR] /home/user/L/src/main/java/edu/stanford/nlp/pipeline/NLP.java:[6,32] cannot find symbol

what should i do ? I'm using stanford 3.4.1 with java 1.6 maven 2.3

using mvn -v

Apache Maven 3.0.5
Maven home: /usr/share/maven
Java version: 1.6.0_38, vendor: Sun Microsystems Inc.
Java home: /usr/lib/jvm/java-6-openjdk-amd64/jre

POM file

<plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
                            <version>2.3</version>
            <configuration>
                <source>1.6</source>
                <target>1.6</target>
            </configuration>
        </plugin>
                    <plugin>
                            <groupId>org.apache.maven.plugins</groupId>
                            <artifactId>maven-surefire-plugin</artifactId>
                            <version>2.3</version>
                            <configuration>
                            <skipTests>true</skipTests>
                            </configuration>
                    </plugin>

来源：https://stackoverflow.com/questions/39792688/failed-to-execute-goal