apache/maven · error · PluginResolutionException

Plugin {} or one of its dependencies could not be resolved:

Error message

Plugin {} or one of its dependencies could not be resolved:
	{}

What it means

Deprecated extension-resolution path in DefaultPluginDependenciesResolver: after reading the descriptor of a core/extension plugin (and warning about relocations), an ArtifactDescriptorException — failure to read the extension's POM — is converted to PluginResolutionException with the combined 'Plugin ... or one of its dependencies could not be resolved' message. Same failure family as the non-deprecated resolver, surfaced when building extension realms.

Source

Thrown at impl/maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultPluginDependenciesResolver.java:206

            for (MavenPluginDependenciesValidator dependenciesValidator : dependenciesValidators) {
                dependenciesValidator.validate(session, pluginArtifact, result);
            }

            pluginArtifact = result.getArtifact();

            if (logger.isWarnEnabled() && !result.getRelocations().isEmpty()) {
                String message =
                        pluginArtifact instanceof RelocatedArtifact relocated ? ": " + relocated.getMessage() : "";
                logger.warn(
                        "The extension {} has been relocated to {}{}",
                        result.getRelocations().get(0),
                        pluginArtifact,
                        message);
            }
            return resolveInternal(plugin, pluginArtifact, dependencyFilter, repositories, session);
        } catch (ArtifactDescriptorException e) {
            throw new PluginResolutionException(plugin, e.getResult().getExceptions(), e);
        }
    }

    @Deprecated
    @Override
    public DependencyResult resolvePlugin(
            Plugin plugin,
            Artifact artifact,
            DependencyFilter dependencyFilter,
            List<RemoteRepository> repositories,
            RepositorySystemSession session)
            throws PluginResolutionException {
        return resolvePluginAndFlatten(plugin, artifact, dependencyFilter, repositories, session);
    }

    @Override
    public DependencyResult resolvePluginAndFlatten(
            Plugin plugin,

View on GitHub (pinned to e4093d4e12)

Solutions

Check the extension plugin's POM is deployed and readable in a reachable repository.
Fix the coordinates/version to one that is fully deployed (POM plus JAR plus parent chain).
Purge the local cache for that group and re-run with mvn -U.
Ensure mirrors expose the repository hosting the extension's parent POM.
If the extension is yours, run mvn deploy on a clean repo and verify the full file set landed.

Example fix

# before: extension POM unreadable (missing parent) while building the extension realm
# after: verify deployment completeness, then force refresh

curl -fsSI https://repo.example.com/org/example/example-build-extension/2.0/example-build-extension-2.0.pom
rm -rf ~/.m2/repository/org/example/example-build-extension
mvn -U verify

Defensive patterns

Strategy: validation

Validate before calling

# validate the extension's full descriptor chain before the build consumes it
repo=https://repo.example.com
for f in example-build-extension-2.0.pom example-build-extension-2.0.jar; do
  curl -fsSI $repo/org/example/example-build-extension/2.0/$f > /dev/null || echo "MISSING: $f"
done
# parent POM referenced by the extension must also resolve
curl -fsSI $repo/org/example/example-parent/1.3/example-parent-1.3.pom > /dev/null || echo 'MISSING parent POM'

Try / catch

try {
    pluginDependenciesResolver.resolveExtension(plugin, repositories, session); // deprecated API
} catch (PluginResolutionException e) {
    if (e.getCause() instanceof ArtifactDescriptorException ade) {
        reportDescriptorFailure(plugin, ade.getResult().getExceptions());
    }
    throw e;
}

Prevention

Keep extension plugins on released versions with complete deployments.
Avoid hand-editing repository paths for extensions; let the repo manager proxy the source repo.
Purge ~/.m2/repository entries for an extension after fixing upstream, then rebuild with -U.
Track deprecation: migrate off the resolvePlugin/resolveExtension APIs when updating embedder code.

When it happens

Trigger: Resolving a <extensions>true</extensions> plugin (or deprecated resolvePlugin/resolveExtension API) whose POM cannot be read: missing POM, invalid XML, unresolvable parent, or transfer failure from the configured repositories.

Common situations: Custom packaging/build extensions whose POM is missing from the corporate repository; extensions whose parent POM lives in a repo not proxied by the mirror; local repo corruption.

Related errors

AI-assisted analysis of apache/maven@e4093d4e12 (2026-08-21). Data as JSON: /api/errors/9f465dc29d21a5e8. Report an issue: GitHub.