Gradle build: "compileKotlin" depends from "compileQuarkusGeneratedSourcesJava"

[jmini]

In a Quarkus project where we have the grpc extension (that generates java code) and kotlin, we sometimes have following error in the build:

FAILURE: Build failed with an exception.

* What went wrong:
Some problems were found with the configuration of task ':<project>:compileKotlin' (type 'KotlinCompile').
  - Gradle detected a problem with the following location: '/_path-to_/<project>/build/classes/java/quarkus-generated-sources'.
    
    Reason: Task ':<project>:compileKotlin' uses this output of task ':<project>:compileQuarkusGeneratedSourcesJava' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed.
    
    Possible solutions:
      1. Declare task ':<project>:compileQuarkusGeneratedSourcesJava' as an input of ':<project>:compileKotlin'.
      2. Declare an explicit dependency on ':<project>:compileQuarkusGeneratedSourcesJava' from ':<project>:compileKotlin' using Task#dependsOn.
      3. Declare an explicit dependency on ':<project>:compileQuarkusGeneratedSourcesJava' from ':<project>:compileKotlin' using Task#mustRunAfter.
    
    For more information, please refer to https://docs.gradle.org/8.10.1/userguide/validation_problems.html#implicit_dependency in the Gradle documentation.
  - Gradle detected a problem with the following location: '/_path-to_/<project>/build/classes/java/quarkus-generated-sources/grpc'.
    
    Reason: Task ':<project>:compileKotlin' uses this output of task ':<project>:compileQuarkusGeneratedSourcesJava' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed.
    
    Possible solutions:
      1. Declare task ':<project>:compileQuarkusGeneratedSourcesJava' as an input of ':<project>:compileKotlin'.
      2. Declare an explicit dependency on ':<project>:compileQuarkusGeneratedSourcesJava' from ':<project>:compileKotlin' using Task#dependsOn.
      3. Declare an explicit dependency on ':<project>:compileQuarkusGeneratedSourcesJava' from ':<project>:compileKotlin' using Task#mustRunAfter.
    
    For more information, please refer to https://docs.gradle.org/8.10.1/userguide/validation_problems.html#implicit_dependency in the Gradle documentation.
  - Gradle detected a problem with the following location: '/_path-to_/<project>/build/classes/java/quarkus-generated-sources/avdl'.
    
    Reason: Task ':<project>:compileKotlin' uses this output of task ':<project>:compileQuarkusGeneratedSourcesJava' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed.
    
    Possible solutions:
      1. Declare task ':<project>:compileQuarkusGeneratedSourcesJava' as an input of ':<project>:compileKotlin'.
      2. Declare an explicit dependency on ':<project>:compileQuarkusGeneratedSourcesJava' from ':<project>:compileKotlin' using Task#dependsOn.
      3. Declare an explicit dependency on ':<project>:compileQuarkusGeneratedSourcesJava' from ':<project>:compileKotlin' using Task#mustRunAfter.
    
    For more information, please refer to https://docs.gradle.org/8.10.1/userguide/validation_problems.html#implicit_dependency in the Gradle documentation.
  - Gradle detected a problem with the following location: '/_path-to_/<project>/build/classes/java/quarkus-generated-sources/avpr'.
    
    Reason: Task ':<project>:compileKotlin' uses this output of task ':<project>:compileQuarkusGeneratedSourcesJava' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed.
    
    Possible solutions:
      1. Declare task ':<project>:compileQuarkusGeneratedSourcesJava' as an input of ':<project>:compileKotlin'.
      2. Declare an explicit dependency on ':<project>:compileQuarkusGeneratedSourcesJava' from ':<project>:compileKotlin' using Task#dependsOn.
      3. Declare an explicit dependency on ':<project>:compileQuarkusGeneratedSourcesJava' from ':<project>:compileKotlin' using Task#mustRunAfter.
    
    For more information, please refer to https://docs.gradle.org/8.10.1/userguide/validation_problems.html#implicit_dependency in the Gradle documentation.
  - Gradle detected a problem with the following location: '/_path-to_/<project>/build/classes/java/quarkus-generated-sources/avsc'.
    
    Reason: Task ':<project>:compileKotlin' uses this output of task ':<project>:compileQuarkusGeneratedSourcesJava' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed.
    
    Possible solutions:
      1. Declare task ':<project>:compileQuarkusGeneratedSourcesJava' as an input of ':<project>:compileKotlin'.
      2. Declare an explicit dependency on ':<project>:compileQuarkusGeneratedSourcesJava' from ':<project>:compileKotlin' using Task#dependsOn.
      3. Declare an explicit dependency on ':<project>:compileQuarkusGeneratedSourcesJava' from ':<project>:compileKotlin' using Task#mustRunAfter.
    
    For more information, please refer to https://docs.gradle.org/8.10.1/userguide/validation_problems.html#implicit_dependency in the Gradle documentation.

So for each "location":

• quarkus-generated-sources
• quarkus-generated-sources/grpc
• quarkus-generated-sources/avdl
• quarkus-generated-sources/avsc

You get one of those warnings.

I do not have a reliable reproducer (and I have the feeling that ./gradlew clean build always works), but the error looks correct to me.

I have the feeling that one reason might be that IDEA does not run the build command but select a set of tasks (probably for performance reasons)

07:01:48: Executing ':assemble :<project>:classes :<project>:testClasses :<project>:integrationTestClasses :<project>:nativeTestClasses :<project>:quarkusGeneratedSourcesClasses :<project>:quarkusTestGeneratedSourcesClasses --stacktrace'...

---

As a "fix" we are adding those to our build.gradle:

tasks.named("compileKotlin") {
    inputs.files(tasks.getByPath("compileQuarkusGeneratedSourcesJava").outputs.files)
}
tasks.named("sourcesJar") {
    inputs.files(tasks.getByPath("compileQuarkusGeneratedSourcesJava").outputs.files)
}

But this looks more an input/output declaration issue inside the quarkus gradle plugin.

Any thoughts on this?

[quarkus-bot]

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