The plugin 'org.apache.maven.plugins:maven-jetty-plugin' does not exist or no valid version could be found

This issue happens when the repository does reach the Mortbay release repo http://jetty.mortbay.org/maven2/release so to be safe I always add the below to the build/plugins node in the pom.xml.

<plugin>
        <groupId>org.mortbay.jetty</groupId>
        <artifactId>maven-jetty-plugin</artifactId>
        <version>6.0.1</version>
      </plugin>