plugin = (Plugin) data;
            }
            trace = trace.getParent();
        }

        Path trackingDir;
        boolean missing = event.getFile() == null;
        if (missing) {
            // missing artifact - let's track the path anyway
            File dir = event.getSession().getLocalRepository().getBasedir();
            dir = new File(

            //
            // idea:idea
            //
            String prefix = tok[0];

            if (numTokens == 2) {
                goal = tok[1];
            } else {
                // goal was missing - pass through to MojoNotFoundException
                goal = "";
            }

            // This is the case where someone has executed a single goal from the command line
            // of the form:

            if (id == null || id.isEmpty()) {
                throw new InvalidRepositoryException("Repository identifier missing", "");
            }

            String url = repo.getUrl();

            if (url == null || url.isEmpty()) {
                throw new InvalidRepositoryException("URL missing for repository " + id, id);
            }

                PrintStream ps = new PrintStream(os);
                ps.println("Unable to load the mojo '" + mojoDescriptor.getGoal() + "' in the plugin '"
                        + pluginDescriptor.getId() + "'. A required class is missing: "
                        + cause.getMessage());
                pluginRealm.display(ps);

                throw new PluginContainerException(mojoDescriptor, pluginRealm, os.toString(), cause);

import org.apache.maven.artifact.versioning.OverConstrainedVersionException;

/**
 * Specific problems during resolution that we want to account for:
 * <ul>
 *   <li>missing metadata</li>
 *   <li>version range violations</li>
 *   <li>version circular dependencies</li>
 *   <li>missing artifacts</li>
 *   <li>network/transfer errors</li>
 *   <li>file system errors: permissions</li>
 * </ul>
 *

    }

    private void printErrors(ArtifactResolutionResult result) {
        if (result.hasMissingArtifacts()) {
            for (Artifact artifact : result.getMissingArtifacts()) {
                System.err.println("Missing: " + artifact);
            }
        }

        if (result.hasExceptions()) {
            for (Exception e : result.getExceptions()) {
                e.printStackTrace();
            }
        }

     * @param foreignImports The packages/types to import from foreign realms, may be {@code null}.
     * @param artifacts The artifacts to add to the realm, may be {@code null}. Unresolved artifacts (i.e. with a
     *            missing file) will automatically be excluded from the realm.
     * @return The created class realm, never {@code null}.
     */
    private ClassRealm createRealm(
            String baseRealmId,
            RealmType type,

                        .exists(settingsFile.getExists())
                        .missing(settingsFile.getMissing())
                        .location("exists", toLocation(settingsFile.getLocation("exists")))
                        .location("missing", toLocation(settingsFile.getLocation("missing")))
                        .build());
            }

                scenario("Selected optional project")
                        .activeOptionalProjects(MODULE_B)
                        .expectResult(MODULE_B),
                scenario("Selected missing optional project")
                        .activeOptionalProjects("non-existing-module")
                        .expectResult(
                                PARENT_MODULE,
                                MODULE_C,

            ByteArrayOutputStream os = new ByteArrayOutputStream(1024);
            PrintStream ps = new PrintStream(os);
            ps.println(
                    "A required class was missing while executing " + mojoDescriptor.getId() + ": " + e.getMessage());
            pluginRealm.display(ps);
            Exception wrapper = new PluginContainerException(mojoDescriptor, pluginRealm, os.toString(), e);