We might want to separate between installation and activation, it might be nice to allow a user to activate/deactivate a plugin instead of having to uninstall and reinstall a plugin in particular cases. This would prevent having to reconfigure the plugin again. For example it might be nice to turn off LDAP authentication without having to uninstall the plugin.

 *
 * @since 3.0
 */
// TODO From a concurrency perspective, this class is not good. The combination of mutable/immutable state is not nice
public class DependencyContext {

    private final MavenProject project;

    private final Collection<String> scopesToCollectForCurrentProject;

    private final Collection<String> scopesToResolveForCurrentProject;

 * it delegates to other components that potentially encounter problems. Then, the problem reporter can focus on
 * providing a simple error message, leaving the donkey work of creating a nice model problem to this component.
 *
 */
public interface ModelProblemCollector {

    /**
     * The collected problems.
     * @return a list of model problems encountered, never {@code null}
     */

            legacySupport.setSession(oldSession);
        }
    }

    /**
     * TODO pluginDescriptor classRealm and artifacts are set as a side effect of this
     *      call, which is not nice.
     * @throws PluginResolutionException
     */
    public ClassRealm getPluginRealm(MavenSession session, PluginDescriptor pluginDescriptor)
            throws PluginResolutionException, PluginManagerException {

    Yoyodyne, Inc., hereby disclaims all copyright interest in the
    program `Gnomovision' (which makes passes at compilers) written by
    James Hacker.

    signature of Ty Coon, 1 April 1989
    Ty Coon, President of Vice

This General Public License does not permit incorporating your program
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 * it delegates to other components that potentially encounter problems. Then, the problem reporter can focus on
 * providing a simple error message, leaving the donkey work of creating a nice model problem to this component.
 *
 */
class DefaultModelProblemCollector implements ModelProblemCollector {

    private final ModelBuilderResult result;

    private List<ModelProblem> problems;

/*

- test projects for each of these
- how to categorize the problems so that the id of the problem can be match to a page with descriptive help and the test
  project
- nice little sample projects that could be run in the core as well as integration tests

All Possible Errors
- invalid lifecycle phase (maybe same as bad CLI param, though you were talking about embedder too)

 * </p>
 * <strong>Note:</strong> This interface is part of work in progress and can be changed or removed without notice.
 */
public interface Builder {
    //
    // Be nice to whittle this down to Session, maybe add task segments to the session. The session really is
    // the place to store reactor related information.
    //
    void build(
            MavenSession session,

     * clone. The only requirement is that invocations of {@link #addRepository(Session, Repository)} on the clone do not affect
     * the state of the original resolver and vice versa.
     *
     * @return The cloned resolver, never {@code null}.
     */
    ModelResolver newCopy();