private final List<SettingsProblem> problems;

    /**
     * Creates a new exception with the specified problems.
     *
     * @param problems The problems that cause this exception, may be {@code null}.
     */
    public SettingsBuildingException(List<SettingsProblem> problems) {
        super(toMessage(problems));

        this.problems = new ArrayList<>();
        if (problems != null) {

        this.problems = (problems != null) ? problems : new ArrayList<>();
    }

    public List<SettingsProblem> getProblems() {
        return problems;
    }

    public void setSource(String source) {
        this.source = source;
    }

    @Override
    public void add(SettingsProblem.Severity severity, String message, int line, int column, Exception cause) {

                if (!modelResult.getProblems().isEmpty()) {
                    List<ModelProblem> problems = modelResult.getProblems();
                    if (logger.isDebugEnabled()) {
                        String problem = (problems.size() == 1) ? "problem" : "problems";
                        String problemPredicate = problem + ((problems.size() == 1) ? " was" : " were");

     *
     * @return The assembled toolchains, never {@code null}.
     */
    PersistedToolchains getEffectiveToolchains();

    /**
     * Return a list of problems, if any.
     *
     * @return a list of problems, never {@code null}.
     */
    List<Problem> getProblems();

                        (problemsCount == 1) ? "problem was" : "problems were",
                        result.getProjectId());

                if (request.isShowErrors()) { // this means -e or -X (as -X enables -e as well)
                    for (ModelProblem problem : result.getProblems()) {
                        String loc = ModelProblemUtils.formatLocation(problem, result.getProjectId());

        }

        if (hasErrors(problems.getProblems())) {
            throw new SettingsBuildingException(problems.getProblems());
        }

        return new DefaultSettingsBuildingResult(userSettings, problems.getProblems());
    }

    private boolean hasErrors(List<SettingsProblem> problems) {
        if (problems != null) {
            for (SettingsProblem problem : problems) {

     * @return The formatted problem location or an empty string if unknown, never {@code null}.
     */
    public static String formatLocation(ModelProblem problem, String projectId) {
        StringBuilder buffer = new StringBuilder(256);

        if (!problem.getModelId().equals(projectId)) {
            buffer.append(problem.getModelId());

            if (!problem.getSource().isEmpty()) {

 * providing a simple error message, leaving the donkey work of creating a nice model problem to this component.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")
public interface ModelProblemCollector {

    /**
     * Adds the specified problem.
     *
     * @param req must not be null
     */

    /**
     * The default implementation is not visible, create it with this factory
     *
     * @param problems starting set of problems, may be {@code null}
     * @return a new instance of a ProblemCollector
     */
    public static ProblemCollector newInstance(List<Problem> problems) {
        return new DefaultProblemCollector(problems);
    }

import org.apache.maven.api.model.Model;

/**
 * Collects problems that are encountered during model building. The primary purpose of this component is to account for
 * the fact that the problem reporter has/should not have information about the calling context and hence cannot provide
 * an expressive source hint for the model problem. Instead, the source hint is configured by the model builder before