quarkusio/quarkus · error · IllegalStateException

name cannot be null

Error message

name cannot be null

What it means

DevServicesResultBuildItem.Builder.build() validates that a service name was set before constructing the result. The name identifies which dev service produced the result and must be non-null. Throwing IllegalStateException here signals the builder was used without calling the mandatory name setter.

Source

Thrown at core/deployment/src/main/java/io/quarkus/deployment/builditem/DevServicesResultBuildItem.java:300

        public DiscoveredServiceBuilder containerId(String containerId) {
            this.containerId = containerId;
            return this;
        }

        public DiscoveredServiceBuilder config(Map<String, String> config) {
            this.config = config;
            return this;
        }

        public DiscoveredServiceBuilder description(String description) {
            this.description = description;
            return this;
        }

        public DevServicesResultBuildItem build() {
            if (name == null) {
                throw new IllegalStateException("name cannot be null");
            }
            return new DevServicesResultBuildItem(name, description, containerId, config);
        }
    }

    public static class OwnedServiceBuilder<T extends Startable> {
        private String name;
        private String description;
        private Map<String, String> config;
        private String serviceName;
        private Object serviceConfig;
        private Supplier<? extends Startable> startableSupplier;
        private Consumer<? extends Startable> postStartAction;
        private Map<String, Function<Startable, String>> applicationConfigProvider;
        private Set<String> highPriorityConfig;
        private final Set<DevServiceConfigDependency<? extends Startable>> dependencies = new HashSet<>();
        private final Set<DevServiceConfigDependency<? extends Startable>> optionalDependencies = new HashSet<>();

View on GitHub (pinned to e1c734241f)

Solutions

1. Call the builder's name-setting method (e.g. .name("my-service")) before .build().
2. Ensure the name matches the service identifier used in the DevServicesRequest/feature priority so the result is attributed correctly.
3. Add a unit test asserting the built item has the expected name to catch regressions.

Example fix

// before
return new DevServicesResultBuildItem.Builder()
        .description("Postgres dev service")
        .config(Map.of("quarkus.datasource.jdbc.url", url))
        .build();
// after
return new DevServicesResultBuildItem.Builder()
        .name("postgres")
        .description("Postgres dev service")
        .config(Map.of("quarkus.datasource.jdbc.url", url))
        .build();

if (builderName == null || builderName.isBlank()) {
    throw new IllegalStateException("DevServicesResultBuildItem name must be set before build()");
}

try {
    DevServicesResultBuildItem result = builder.build();
} catch (IllegalStateException e) {
    if ("name cannot be null".equals(e.getMessage())) {
        // set the service name and rebuild
    }
    throw e;
}

When it happens

Trigger: Building a DevServicesResultBuildItem via its builder without calling the method that sets name (e.g. new DevServicesResultBuildItem.Builder() ... .build() with name never assigned).

Common situations: Extension authors writing custom dev service support who construct the result at the end of a startSuppliers method and forget the name; refactoring that renames/removes the name-setting call.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• One of either visitorFunction or inputTransformer must be se
• Dev services for ${request.getName()} requires a startable s
• Either location or predicate must be set
• Predicate already set
• Location already set

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/7870b05492d023e7. Report an issue: GitHub.