apache/maven · error · ProjectBuildingException

Invalid remote repository {}

Error message

Invalid remote repository {}

What it means

Thrown by the legacy DefaultMavenProjectBuilder while converting <repositories> declared in a POM into ArtifactRepository instances. repositorySystem.buildArtifactRepository() (followed by mirror/proxy/auth injection) throws InvalidRepositoryException when the repository definition is unusable - typically an invalid id or malformed URL - and it is rethrown as ProjectBuildingException with message 'Invalid remote repository <definition>'.

Source

Thrown at compat/maven-compat/src/main/java/org/apache/maven/project/DefaultMavenProjectBuilder.java:150

         * This provides backward-compat with 2.x that allowed plugins like the maven-remote-resources-plugin:1.0 to
         * populate the builder configuration with model repositories instead of artifact repositories.
         */

        if (repositories != null) {
            boolean normalized = false;

            List<ArtifactRepository> repos = new ArrayList<>(repositories.size());

            for (Object repository : repositories) {
                if (repository instanceof Repository repositoryInstance) {
                    try {
                        ArtifactRepository repo = repositorySystem.buildArtifactRepository(repositoryInstance);
                        repositorySystem.injectMirror(request.getRepositorySession(), Arrays.asList(repo));
                        repositorySystem.injectProxy(request.getRepositorySession(), Arrays.asList(repo));
                        repositorySystem.injectAuthentication(request.getRepositorySession(), Arrays.asList(repo));
                        repos.add(repo);
                    } catch (InvalidRepositoryException e) {
                        throw new ProjectBuildingException("", "Invalid remote repository " + repository, e);
                    }
                    normalized = true;
                } else {
                    repos.add((ArtifactRepository) repository);
                }
            }

            if (normalized) {
                return repos;
            }
        }

        return (List<ArtifactRepository>) repositories;
    }

    private ProjectBuildingException transformError(ProjectBuildingException e) {
        if (e.getCause() instanceof ModelBuildingException) {
            return new InvalidProjectModelException(e.getProjectId(), e.getMessage(), e.getPomFile());

View on GitHub (pinned to e4093d4e12)

Solutions

1. Inspect the exact repository element echoed in the message and fix its <url> and <id> (scheme, host, path, no unresolved properties)
2. Verify the URL opens outside Maven (curl) and uses a supported protocol (https/http)
3. Move environment-specific repos to settings.xml profiles instead of the POM, so CI machines get correct mirrors
4. If the repo sits in a parent POM you do not control, override or neutralize it in settings.xml
5. Rebuild with -X to see which inject* step rejected the repository

Example fix

<!-- before -->
<repositories>
  <repository>
    <id>corp</id>
    <url>htp://nexus.corp.example/repo</url>
  </repository>
</repositories>
<!-- after -->
<repositories>
  <repository>
    <id>corp</id>
    <url>https://nexus.corp.example/repo</url>
  </repository>
</repositories>

// Sanity-check a repository definition before building a project with it
URI u = URI.create(repository.getUrl());
if (u.getScheme() == null || !("http".equals(u.getScheme()) || "https".equals(u.getScheme()))) {
    throw new IllegalArgumentException("Unsupported repo URL: " + repository.getUrl());
}

When it happens

Trigger: A POM <repositories><repository> entry with a malformed URL (wrong/unknown protocol, unparseable URI) or an otherwise invalid definition (bad id characters, unreadable layout) such that buildArtifactRepository or the inject* calls fail during project building.

Common situations: Typos in repository URLs (e.g. 'htp://', missing scheme, stray spaces or ${} left unresolved); internal Nexus/Artifactory URLs copied with placeholders; plugin/publisher POMs with exotic protocols not enabled in the resolver; corporate mirrors defined via settings.xml conflicting with POM entries.

Related errors

• URL missing for repository " + id
• URL missing for repository {}
• Repository identifier missing
• Repository identifier missing
• Cannot find ArtifactRepositoryLayout instance for: %s %s

AI-assisted analysis of apache/maven@e4093d4e12 (2026-08-21). Data as JSON: /api/errors/e204579d2bde2eae. Report an issue: GitHub.