Currently, mojo configuration is done externally to the container, in the
  DefaultPluginManager in the maven-core API. In order to get from here to
  there, we need to do several things to add capability to the default
  configuration of plexus. This document will detail those changes.

Container Enhancements

* ExpressionEvaluator

  Currently, the expression evaluator used to resolve configuration values

When a plugin is installed we may want to check the license and make users agree. We may also want to unpack the given plugin in a particular location.

     | or the command line, profiles have to have an ID that is unique.
     |
     | An encouraged best practice for profile identification is to use a consistent naming convention
     | for profiles, such as 'env-dev', 'env-test', 'env-production', 'user-jdcasey', 'user-brett', etc.
     | This will make it more intuitive to understand what the set of introduced profiles is attempting

log.debug("About to do something to object " + name); } name.bar(); } catch (IllegalStateExceptio e) { log.error("Something bad happened to " + name, e); } ... } Unless you configure things differently, all log output will be written to System.err. Therefore, you really will want to review the remainder of this page in order to understand how to configure logging for your application. Configuring the Commons Logging Package Choosing a LogFactory Implementation From an application perspective, the...

     *
     * @param pluginDescriptor The plugin descriptor in which to save the class realm and the plugin artifacts, must not
     *            be {@code null}.
     * @param session The build session from which to pick the current project and repository settings, must not be
     *            {@code null}.
     * @param parent The parent class realm for the plugin, may be {@code null} to use the Maven core realm.

    void addEdge(Vertex from, Vertex to) throws CycleDetectedException {
        from.children.add(to);
        to.parents.add(from);
        List<String> cycle = findCycle(to);
        if (cycle != null) {
            // remove edge which introduced cycle
            removeEdge(from, to);
            throw new CycleDetectedException(

        // do nothing
    }

    /**
     * Invoked after all projects were built.
     *
     * This callback is intended to allow extensions to perform cleanup of any
     * allocated external resources after the build. It is invoked on best-effort
     * basis and may be missed due to an Error or RuntimeException in Maven core
     * code.
     *
     * @param session the Maven session

     */
    private final Map<PathType, List<Path>> dispatchedPaths;

    /**
     * The dependencies together with the path to each dependency.
     */
    private final Map<Dependency, Path> dependencies;

    /**
     * Information about modules in the main output. This field is initially null and is set to a non-null

     * parameters that would be required to delegate to a stateless component. Saving the session (in a thread-local
     * variable) is our best effort to record any state that is required to enable proper delegation.
     *
     * @param session The currently active session, may be {@code null}.
     */
    void setSession(MavenSession session);

    /**
     * Gets the currently active session.

 * <p>
 * Should only be implemented by DebugResolutionListener.  Remove this
 * when the ResolutionListener interface deprecation of the manageArtifact
 * method (and the [yet to be done] addition of these methods to that
 * interface) has had a chance to propagate to all interested plugins.
 */
@Deprecated
public interface ResolutionListenerForDepMgmt {
    void manageArtifactVersion(Artifact artifact, Artifact replacement);