value = basedir + expression.substring(pathSeparator);
            }
        }

        /*
         * MNG-4312: We neither have reserved all of the above magic expressions nor is their set fixed/well-known (it
         * gets occasionally extended by newer Maven versions). This imposes the risk for existing plugins to
         * unintentionally use such a magic expression for an ordinary property. So here we check whether we

 * that the plugins/mojos can be used in arbitrary contexts. In particular, the mojos can be used for ordinary build
 * plugins as well as special purpose plugins like reports.
 *
 * @since 3.0
 */
@Named
@Singleton
public class DefaultMavenPluginManager implements MavenPluginManager {

    /**
     * <p>

     *
     * <strong>Implementation note:</strong> while this method return type is {@link Map}, the
     * returned map instance implements {@link java.util.concurrent.ConcurrentMap} as well.
     *
     * @throws org.apache.maven.api.services.MavenException if not called from the within a mojo execution
     */
    @Nonnull
    Map<String, Object> getPluginContext(@Nonnull Project project);

 * <li>unlimited number of version components,</li>
 * <li>version components in the text can be digits or strings,</li>
 * <li>strings are checked for well-known qualifiers and the qualifier ordering is used for version ordering.
 *     Well-known qualifiers (case insensitive) are:<ul>
 *     <li><code>alpha</code> or <code>a</code></li>
 *     <li><code>beta</code> or <code>b</code></li>

        // This is often an artifact like a POM that is taken from disk and we already have hold of the
        // file reference. But this may be a Maven Plugin that we need to resolve from a remote repository
        // as well as its dependencies.

        if (request.isResolveRoot() /* && rootArtifact.getFile() == null */) {
            try {
                resolve(rootArtifact, request.getRemoteRepositories(), session);

- 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)
- <module> specified is not found
- malformed settings
- malformed POM

 * is thread safe.
 * <p>
 * Important: Given the instance of supplier memorizes the supplier {@link RepositorySystem} instance it supplies,
 * their lifecycle is shared as well: once supplied repository system is shut-down, this instance becomes closed as
 * well. Any subsequent {@code getXXX} method invocation attempt will fail with {@link IllegalStateException}.
 */
public class RepositorySystemSupplier implements Supplier<RepositorySystem> {

                }
            }
        }

        /*
         * MNG-4312: We neither have reserved all of the above magic expressions nor is their set fixed/well-known (it
         * gets occasionally extended by newer Maven versions). This imposes the risk for existing plugins to
         * unintentionally use such a magic expression for an ordinary property. So here we check whether we

     * dependency management entries in transitive dependency POMs. Maven 4 enables "transitivity" by default, hence
     * unlike Maven2, obeys dependency management entries deep in dependency graph as well.
     * <p>
     * Default: {@code "true"}.
     *
     * @since 4.0.0
     */
    private static final String MAVEN_RESOLVER_DEPENDENCY_MANAGER_TRANSITIVITY_KEY =

                for (ReportPlugin element : src) {
                    if (element.isInherited()) {
                        // NOTE: Enforce recursive merge to trigger merging/inheritance logic for executions as well
                        ReportPlugin plugin = ReportPlugin.newInstance(false);
                        plugin = mergeReportPlugin(plugin, element, sourceDominant, context);