quarkusio/quarkus · error · IllegalArgumentException

You're not expected to use the unnamed module as identifier

Error message

You're not expected to use the unnamed module as identifier - please check the javadoc

What it means

ModuleEnableNativeAccessBuildItem requests JPMS native access for a named module. The unnamed module (the classpath, ModuleOpenBuildItem.ALL_UNNAMED) is not a valid identifier here — the javadoc restricts this item to named modules — so the constructor throws IllegalArgumentException when ALL_UNNAMED is passed. Assert also guarantees moduleName itself is non-empty.

Source

Thrown at core/deployment/src/main/java/io/quarkus/deployment/builditem/ModuleEnableNativeAccessBuildItem.java:28

 * when generating a runnable Jar we can only generate an Enable-Native-Access entry in the Manifest
 * for the modules normally identified by ALL-UNNAMED.
 * This is considered acceptable at the time of writing as extensions are generally placed on the
 * classpath for both fast-jar and uber-jar packaging formats. We expect this to evolve as further packaging
 * formats are introduced which would better leverage the module system.
 * We specifically don't allow enabling native access for "ALL-UNNAMED" explicitly while using this API to
 * encourage using the module names that a library has or will have in the near future:
 * for this reason, when a module name is provided which doesn't exist, we map it to the unnamed module.
 * It is not possible to allow native code access to other modules via an agent, other approaches
 * will need to be identified to reconfigure at runtime.
 */
public final class ModuleEnableNativeAccessBuildItem extends MultiBuildItem {

    private final String moduleName;

    public ModuleEnableNativeAccessBuildItem(final String moduleName) {
        this.moduleName = Assert.checkNotEmptyParam("moduleName", moduleName);
        if (ModuleOpenBuildItem.ALL_UNNAMED.equals(moduleName)) {
            throw new IllegalArgumentException(
                    "You're not expected to use the unnamed module as identifier - please check the javadoc");
        }
    }

    public String moduleName() {
        return moduleName;
    }
}

View on GitHub (pinned to e1c734241f)

Solutions

1. Pass the actual named module, e.g. new ModuleEnableNativeAccessBuildItem("org.apache.commons.lang3"), matching the module-info name of the library.
2. If the target code runs on the classpath (unnamed module), it already has no module restrictions for this purpose — remove the build item instead.
3. If you need ALL-UNNAMED semantics, look at ModuleOpenBuildItem usage for opens where ALL_UNNAMED is valid as the opening module, and drop the native-access request.

Example fix

// before
buildProducer.produce(new ModuleEnableNativeAccessBuildItem(ModuleOpenBuildItem.ALL_UNNAMED));
// after
buildProducer.produce(new ModuleEnableNativeAccessBuildItem("org.graalvm.nativeimage"));

if (ModuleOpenBuildItem.ALL_UNNAMED.equals(moduleName)) {
    throw new IllegalArgumentException("ModuleEnableNativeAccessBuildItem requires a named module, not ALL-UNNAMED");
}
produce(new ModuleEnableNativeAccessBuildItem(moduleName));

boolean isValidNamedModule(String moduleName) {
    return moduleName != null && !moduleName.isBlank() && !ModuleOpenBuildItem.ALL_UNNAMED.equals(moduleName);
}

try {
    produce(new ModuleEnableNativeAccessBuildItem(moduleName));
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("unnamed module")) {
        log.warnf("Skipping native-access request for unnamed module '%s'", moduleName);
        return;
    }
    throw e;
}

When it happens

Trigger: Constructing new ModuleEnableNativeAccessBuildItem(ModuleOpenBuildItem.ALL_UNNAMED) or new ModuleEnableNativeAccessBuildItem("ALL-UNNAMED"), i.e. passing the unnamed-module sentinel as moduleName.

Common situations: Extension code parameterizing module names from config and defaulting to ALL-UNNAMED; misunderstanding of the javadoc assuming the unnamed module can be targeted like with opens.

Related errors

• At least one package name must be specified
• Failed to redefine module ${moduleName}
• Failed to invoke implAddOpens
• Failed to open path tree with root %s
• Dev services for ${request.getName()} requires a startable s

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/4bc2cdb973e9a687. Report an issue: GitHub.