Quarkus fails to start up with composite Gradle build when using Kotlin (Java works correctly)

[lspahija]

Describe the bug

When both the root gradle project and the gradle subproject in a composite gradle build use Quarkus with Kotlin, the project throws a runtime exception and fails to start up.

Expected behavior

The project starts up successfully.

Actual behavior

The following exception is thrown at runtime and the project fails to start up:

2025-04-17 14:01:57,148 ERROR [io.qua.dep.dev.IsolatedDevModeMain] (main) Failed to start quarkus: java.lang.RuntimeException: io.quarkus.builder.BuildException: Build failure: Build failed due to errors
        [error]: Build step io.quarkus.arc.deployment.ArcProcessor#validate threw an exception: jakarta.enterprise.inject.spi.DeploymentException: jakarta.enterprise.inject.UnsatisfiedResolutionException: Unsatisfied dependency for type org.example.SomeBean and qualifiers [@Default]
        - injection target: parameter 'someBean' of org.example.ExampleResource constructor
        - declared on CLASS bean [types=[org.example.ExampleResource, java.lang.Object], qualifiers=[@Default, @Any], target=org.example.ExampleResource]
        at io.quarkus.arc.processor.BeanDeployment.processErrors(BeanDeployment.java:1581)
        at io.quarkus.arc.processor.BeanDeployment.init(BeanDeployment.java:338)
        at io.quarkus.arc.processor.BeanProcessor.initialize(BeanProcessor.java:178)
        at io.quarkus.arc.deployment.ArcProcessor.validate(ArcProcessor.java:489)
        at java.base/java.lang.invoke.MethodHandle.invokeWithArguments(MethodHandle.java:733)
        at io.quarkus.deployment.ExtensionLoader$3.execute(ExtensionLoader.java:856)
        at io.quarkus.builder.BuildContext.run(BuildContext.java:255)
        at org.jboss.threads.ContextHandler$1.runWith(ContextHandler.java:18)
        at org.jboss.threads.EnhancedQueueExecutor$Task.doRunWith(EnhancedQueueExecutor.java:2675)
        at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2654)
        at org.jboss.threads.EnhancedQueueExecutor.runThreadBody(EnhancedQueueExecutor.java:1627)
        at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1594)
        at java.base/java.lang.Thread.run(Thread.java:1583)
        at org.jboss.threads.JBossThread.run(JBossThread.java:499)
Caused by: jakarta.enterprise.inject.UnsatisfiedResolutionException: Unsatisfied dependency for type org.example.SomeBean and qualifiers [@Default]
        - injection target: parameter 'someBean' of org.example.ExampleResource constructor
        - declared on CLASS bean [types=[org.example.ExampleResource, java.lang.Object], qualifiers=[@Default, @Any], target=org.example.ExampleResource]
        at io.quarkus.arc.processor.Beans.resolveInjectionPoint(Beans.java:547)
        at io.quarkus.arc.processor.BeanInfo.init(BeanInfo.java:689)
        at io.quarkus.arc.processor.BeanDeployment.init(BeanDeployment.java:323)
        ... 12 more

If the root project doesn't inject any beans from the dependency and instead only accesses a plain Kotlin class from the dependency, then this exception is thrown instead and the project still fails to start up:

2025-04-17 14:12:09,066 WARN  [io.qua.dep.ste.ReflectiveHierarchyStep] (build-4) Unable to properly register the hierarchy of the following classes for reflection as they are not in the Jandex index:
     - org.example.SomeDataClass (source: ResteasyReactiveProcessor > org.example.ExampleResource[org.example.SomeDataClass hello()] > org.example.SomeDataClass > org.example.SomeDataClass)
Consider adding them to the index either by creating a Jandex index for your dependency via the Maven plugin, an empty META-INF/beans.xml or quarkus.index-dependency properties.
2025-04-17 14:12:09,126 ERROR [io.qua.run.Quarkus] (Quarkus Main Thread) Error running Quarkus: java.lang.ExceptionInInitializerError
        at java.base/jdk.internal.misc.Unsafe.allocateInstance(Native Method)
        at java.base/java.lang.invoke.DirectMethodHandle.allocateInstance(DirectMethodHandle.java:501)
        at io.quarkus.runtime.Quarkus.run(Quarkus.java:79)
        at io.quarkus.runtime.Quarkus.run(Quarkus.java:51)
        at io.quarkus.runtime.Quarkus.run(Quarkus.java:144)
        at io.quarkus.runner.GeneratedMain.main(Unknown Source)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
        at java.base/java.lang.reflect.Method.invoke(Method.java:580)
        at io.quarkus.runner.bootstrap.StartupActionImpl$1.run(StartupActionImpl.java:116)
        at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: java.lang.RuntimeException: Failed to start quarkus
        at io.quarkus.runner.ApplicationImpl.<clinit>(Unknown Source)
        ... 10 more
Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: org.example.SomeDataClass
        at org.jboss.resteasy.reactive.common.util.types.TypeSignatureParser.loadClass(TypeSignatureParser.java:165)
        at org.jboss.resteasy.reactive.common.util.types.TypeSignatureParser.parseReference(TypeSignatureParser.java:146)
        at org.jboss.resteasy.reactive.common.util.types.TypeSignatureParser.parseType(TypeSignatureParser.java:54)
        at org.jboss.resteasy.reactive.common.util.types.TypeSignatureParser.parse(TypeSignatureParser.java:170)
        at org.jboss.resteasy.reactive.server.core.startup.RuntimeResourceDeployment.buildResourceMethod(RuntimeResourceDeployment.java:389)
        at org.jboss.resteasy.reactive.server.core.startup.RuntimeDeploymentManager.deploy(RuntimeDeploymentManager.java:137)
        at io.quarkus.resteasy.reactive.server.runtime.ResteasyReactiveRecorder.createDeployment(ResteasyReactiveRecorder.java:161)
        at io.quarkus.runner.recorded.ResteasyReactiveProcessor$setupDeployment944680882.deploy_0(Unknown Source)
        at io.quarkus.runner.recorded.ResteasyReactiveProcessor$setupDeployment944680882.deploy(Unknown Source)
        ... 11 more
Caused by: java.lang.ClassNotFoundException: org.example.SomeDataClass
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526)
        at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass(QuarkusClassLoader.java:569)
        at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass(QuarkusClassLoader.java:517)
        at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass(QuarkusClassLoader.java:569)
        at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass(QuarkusClassLoader.java:517)
        at java.base/java.lang.Class.forName0(Native Method)
        at java.base/java.lang.Class.forName(Class.java:534)
        at java.base/java.lang.Class.forName(Class.java:513)
        at org.jboss.resteasy.reactive.common.util.types.TypeSignatureParser.loadClass(TypeSignatureParser.java:163)
        ... 19 more

How to Reproduce?

Reproducer: https://github.com/lspahija/quarkus-complex-build-bug-reproducer

There are two branches: not-working-kotlin (default branch) and works-java

Steps to reproduce the behavior:

1. git clone https://github.com/lspahija/quarkus-complex-build-bug-reproducer
2. cd quarkus-complex-build-bug-reproducer
3. ./gradlew quarkusDev
4. see exception in the console and note that the project has failed to start up

If you wish to see the equivalent java project working successfully:

1. git checkout works-java
2. ./gradlew quarkusDev
3. note that everything works fine

Output of uname -a or ver

Darwin MacBookPro 24.3.0 Darwin Kernel Version 24.3.0: Thu Jan 2 20:24:16 PST 2025; root:xnu-11215.81.4~3/RELEASE_ARM64_T6000 arm64

Output of java -version

openjdk version "21.0.6" 2025-01-21 LTS OpenJDK Runtime Environment Zulu21.40+17-CA (build 21.0.6+7-LTS) OpenJDK 64-Bit Server VM Zulu21.40+17-CA (build 21.0.6+7-LTS, mixed mode, sharing)

Quarkus version or git rev

3.21.3

Build tool (ie. output of mvnw --version or gradlew --version)

Gradle 8.12

Additional information

No response

[quarkus-bot]

/cc @geoand (kotlin), @glefloch, @quarkusio/devtools

[lspahija]

I may have made the mistake of submitting this right before the Easter break.

@geoand, @glefloch, care to have a look?

[geoand]

I have no idea what the issue is. Perhaps @aloubyansky has some tips

[lspahija]

@aloubyansky do you, in fact, have any tips? 😃

To summarize, there are two identical projects in the bug report above, save for one difference: the one uses Java and the other Kotlin. The Java variant works fine. The Kotlin variant throws a Quarkus-related runtime exception during startup and fails to start up successfully.

[aloubyansky]

@lspahija thanks a lot for the reproducer. I'll look into it and add it to our testsuite.

[n-hass]

I have also hit this issue with Gradle 8.13 + latest Quarkus LTS (3.20.0) and have made a reproducer that mimics my real project. My real project also has this issue on Quarkus 3.15.3. The project layout is slightly different to @lspahija's - just two projects next to each other at top-level, one the Quarkus and one a Kotlin Multiplatform library with JVM artifacts. I get the NoClassDefFoundError when running quarkusTest, but running just plain test reveals a ClassCastException when using kotlin-serialisation, and I think this is related/part of this issue.

class MyClass$$serializer cannot be cast to class kotlinx.serialization.SerializationStrategy (MyClass$$serializer is in unnamed module of loader 'app'; kotlinx.serialization.SerializationStrategy is in unnamed module of loader io.quarkus.bootstrap.classloading.QuarkusClassLoader @dcfda20)`

Reproducer available here: https://github.com/n-hass/quarkus-issue-47430

Moving the dependency into the Quarkus project from the external project that is included resolves the issue.

[geoand]

@n-hass @lspahija can you please try #47730 and see if it fixes your issue?

[aloubyansky]

#47730 fixes the test part of the reproducer provided by @n-hass but not the quarkusTest one, unfortunately. We'll need to investigate it further.

Thanks for the reproducer @n-hass!

[lspahija]

Built @aloubyansky's branch locally and my reproducer now works fine!

The reason I created the reproducer is because we have a more complex internal project at American Express that uses Quarkus and this was causing an issue there.

Unfortunately I would have trouble building Quarkus locally on my work machine because of firewalls making it necessary to configure proxies to artifact repositories.

I'm guessing there's no snapshot version available containing the change until the PR is merged into main?

[aloubyansky]

@lspahija thanks for checking the fix. We do publish SNAPSHOTs but from the main branch, which means a PR would have to be merged for the changes to become available in a published SNAPSHOT build. Some more information can be found here https://github.com/quarkusio/quarkus/blob/main/CONTRIBUTING.md#using-snapshots