quarkusio/quarkus · error · java.lang.UnsupportedOperationException

Module name not supported while building

Error message

Module name not supported while building

What it means

ResolvedDependencyBuilder is a builder for ResolvedDependency; the JPMS module name is only computed on the built, resolved object, not during construction. Calling getModuleName() on the builder throws UnsupportedOperationException by design.

Source

Thrown at independent-projects/bootstrap/app-model/src/main/java/io/quarkus/maven/dependency/ResolvedDependencyBuilder.java:163

    }

    @Override
    public Collection<ArtifactCoords> getDependencies() {
        return deps;
    }

    public ResolvedDependencyBuilder setDirectDependencies(Collection<Dependency> directDeps) {
        this.directDeps = directDeps;
        return this;
    }

    @Override
    public Collection<Dependency> getDirectDependencies() {
        return directDeps;
    }

    public String getModuleName() {
        throw new UnsupportedOperationException("Module name not supported while building");
    }

    @Override
    public ResolvedDependency build() {
        return new ResolvedArtifactDependency(this);
    }

    @Override
    public Map<String, Object> asMap(MappableCollectionFactory factory) {
        final Map<String, Object> map = factory.newMap(7);
        putInMap(this, map, factory);
        return map;
    }
}

View on GitHub (pinned to e1c734241f)

Solutions

1. Call build() first and invoke getModuleName() on the resulting ResolvedDependency
2. Restructure code so module-name inspection happens after dependency resolution completes, not during building
3. Check the variable's static type; if it is ResolvedDependencyBuilder, you are in the build phase

Example fix

// before
String name = builder.getModuleName();
// after
String name = builder.build().getModuleName();

String safeModuleName(Object o) {
    return (o instanceof ResolvedDependency rd)
        ? rd.getModuleName()
        : null; // builders do not support getModuleName
}

String moduleNameIfResolved(Object o) {
    if (!(o instanceof ResolvedDependency)) return null;
    return ((ResolvedDependency) o).getModuleName();
}

try {
    return builder.getModuleName();
} catch (UnsupportedOperationException e) {
    return builder.build().getModuleName(); // only valid post-build
}

When it happens

Trigger: Calling getModuleName() on a ResolvedDependencyBuilder instance (e.g. while iterating builder objects during dependency resolution) instead of on the ResolvedDependency returned by build().

Common situations: Code refactored from using ResolvedDependency directly to the builder API, accidentally calling getModuleName on the builder mid-resolution; debug code inspecting builders.

Related errors

• You're not expected to use the unnamed module as identifier
• At least one package name must be specified
• The unnamed module cannot be opened to other modules
• The unnamed module cannot be used as an opening module ident
• Failed to redefine module ${moduleName}

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/07d4b17b0b9165c1. Report an issue: GitHub.