Maven is not adding a library to the final JAR

Question

I have a maven project that contains a set of dependencies that are local. I am using a Maven plugin to create a fat jar. Part of my pom.xml is the following:

<plugins>
        <plugin>
            <artifactId>maven-assembly-plugin</artifactId>
            <configuration>
                <archive>
                    <manifest>
                        <mainClass></mainClass>
                    </manifest>
                </archive>
                <descriptorRefs>
                    <descriptorRef>
                         jar-with-dependencies
                    </descriptorRef>
                </descriptorRefs>
            </configuration>
            <executions>
                <execution>
                    <id>make-assembly</id>
                    <phase>package</phase>
                    <goals>
                        <goal>single</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>

When I try to run the JAR using: java -cp myjar.jar MainClass I receive a runtime exception because it seems that a library is missing.

The library is defined as:

<dependency>
            <groupId>edu.washington.knowitall</groupId>
            <artifactId>reverb2</artifactId>
            <version>2.0.1</version>
            <scope>system</scope>
            <systemPath>${project.basedir}/lib/reverb-latest.jar</systemPath>
        </dependency>

If I run my JAR using: java -cp myjar.jar:lib/reverb-latest.jar Everything runs perfectly.

However, If I run my main class inside eclipse everything runs perfectly.

I create the package using:

mvn clean
mvn install