xml.namespace="http://maven.apache.org/METADATA/${version}"
  xml.schemaLocation="https://maven.apache.org/xsd/repository-metadata-${version}.xsd">
  <id>repository-metadata</id>
  <name>Metadata</name>
  <description><![CDATA[
    <p>Per-directory repository metadata <code>repository-metadata.xml</code>.</p>

            org.eclipse.aether.metadata.Metadata metadata,
            ArtifactRepository repository) {
        if (metadata != null && metadata.getFile() != null && metadata.getFile().isFile()) {
            try {
                Map<String, ?> options = Collections.singletonMap(MetadataReader.IS_STRICT, Boolean.FALSE);

                Metadata repoMetadata = metadataReader.read(metadata.getFile(), options);

                return result;
            }
        }

        Metadata metadata;

        if (RELEASE.equals(version)) {
            metadata = new DefaultMetadata(
                    artifact.getGroupId(), artifact.getArtifactId(), MAVEN_METADATA_XML, Metadata.Nature.RELEASE);
        } else if (LATEST.equals(version)) {
            metadata = new DefaultMetadata(
                    artifact.getGroupId(),

            org.eclipse.aether.metadata.Metadata metadata,
            ArtifactRepository repository) {
        if (metadata != null && metadata.getFile() != null && metadata.getFile().isFile()) {
            try {
                Map<String, ?> options = Collections.singletonMap(MetadataReader.IS_STRICT, Boolean.FALSE);

                Metadata pluginGroupMetadata = metadataReader.read(metadata.getFile(), options);

        private final Metadata metadata;

        ArtifactMetadataAdapter(Metadata metadata) {
            this.metadata = metadata;
        }

        public boolean storedInArtifactVersionDirectory() {
            return !metadata.getVersion().isEmpty();
        }

        public boolean storedInGroupDirectory() {
            return metadata.getArtifactId().isEmpty();
        }

                return result;
            }
        }

        Metadata metadata;

        if (RELEASE.equals(version)) {
            metadata = new DefaultMetadata(
                    artifact.getGroupId(), artifact.getArtifactId(), MAVEN_METADATA_XML, Metadata.Nature.RELEASE);
        } else if (LATEST.equals(version)) {
            metadata = new DefaultMetadata(
                    artifact.getGroupId(),

        // snapshot timestamp, or some other timestamp later encoded into the metadata.
        // TODO this needs to be repeated here so the merging doesn't interfere with the written metadata
        //  - we'd be much better having a pristine input, and an ongoing metadata for merging instead

        Map<ArtifactRepository, Metadata> previousMetadata = new HashMap<>();
        ArtifactRepository selected = null;

- parent POM missing (in both the repository + relative path)
- component not found

Plugins:
- plugin metadata missing
- plugin metadata retrieval problem
- plugin artifact missing
- plugin artifact retrieval problem
- plugin dependency metadata missing
- plugin dependency metadata retrieval problem
- plugin configuration problem

            RequestTrace trace,
            Metadata metadata,
            ArtifactRepository repository,
            VersionRangeResult result) {
        Versioning versioning = null;
        try {
            if (metadata != null) {
                try (SyncContext syncContext = syncContextFactory.newInstance(session, true)) {
                    syncContext.acquire(null, Collections.singleton(metadata));

import org.apache.maven.artifact.metadata.ArtifactMetadataRetrievalException;
import org.apache.maven.artifact.metadata.ArtifactMetadataSource;
import org.apache.maven.artifact.metadata.ResolutionGroup;
import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.artifact.repository.metadata.ArtifactRepositoryMetadata;
import org.apache.maven.artifact.repository.metadata.Metadata;