} else {
            boolean fallback = false;

            String[] tok = part1.split("\\.");
            int idx = 0;
            if (idx < tok.length) {
                majorVersion = getNextIntegerToken(tok[idx++]);
                if (majorVersion == null) {
                    fallback = true;
                }
            } else {
                fallback = true;
            }

            /*
             * JAR file: can contain only one module, with descriptor at the root.
             * If no descriptor, the "Automatic-Module-Name" manifest attribute is
             * taken as a fallback.
             */
            try (JarFile jar = new JarFile(path.toFile())) {
                ZipEntry entry = jar.getEntry(MODULE_INFO);
                if (entry != null) {
                    String name = null;

        private final ArtifactRepositoryLayout fallback;

        UnknownRepositoryLayout(String id, ArtifactRepositoryLayout fallback) {
            this.id = id;
            this.fallback = fallback;
        }

        public String getId() {
            return id;
        }

        public String pathOf(Artifact artifact) {
            return fallback.pathOf(artifact);
        }

                    projectSelector.getOptionalProjectsBySelectors(request, allSortedProjects, optionalSelectors));

            // it can be empty when an optional project is missing from the reactor, fallback to returning all projects
            if (!selectedProjects.isEmpty()) {
                result = new ArrayList<>(selectedProjects);

                result = includeAlsoMakeTransitively(result, request, graph);

                                } catch (Throwable e) {
                                  echo "Failure checkout ITs branch: ${ITS_BRANCH} - fallback master branch"
                                  checkout([$class: 'GitSCM',
                                          branches: [[name: "*/master"]],

                if (connectTimeoutXml != null) {
                    connectTimeout = Integer.parseInt(connectTimeoutXml.getValue());
                } else {
                    // fallback configuration name
                    PlexusConfiguration httpConfiguration = config.getChild("httpConfiguration", false);
                    if (httpConfiguration != null) {

        } catch (ExpressionEvaluationException e) {
            // not important
            // will be reported during Mojo fields populate
        }

        // fallback - in case of error in expressionEvaluator
        return false;
    }

    @Override
    public final void validate(
            MavenSession mavenSession,
            MojoDescriptor mojoDescriptor,

@REM ==== END VALIDATION ====

:init

set "CLASSWORLDS_CONF=%MAVEN_HOME%\bin\m2.conf"

@REM Find the project basedir, i.e., the directory that contains the directory ".mvn".
@REM Fallback to current working directory if not found.

set "EXEC_DIR=%CD%"
set "WDIR=%EXEC_DIR%"

@REM Look for the --file switch and start the search for the .mvn directory from the specified
@REM POM location, if supplied.

set FILE_ARG=
:arg_loop

                        } catch (Throwable e) {
                          echo "Failure checkout ITs branch: ${ITS_BRANCH} - fallback master branch"
                          checkout([$class: 'GitSCM',
                                  branches: [[name: "*/master"]],

            /*
             * JAR file: can contain only one module, with descriptor at the root.
             * If no descriptor, the "Automatic-Module-Name" manifest attribute is
             * taken as a fallback.
             */
            try (JarFile jar = new JarFile(path.toFile())) {
                ZipEntry entry = jar.getEntry(MODULE_INFO);
                if (entry != null) {
                    String name = null;