Pass different system properties per project for gradle multi project builds when starting in parallel

[ls-bit]

Hi,
we have a multi-project gradle build containing different quarkus applications and start them in parallel. We want to configure different quarkus profiles and debug ports per project based on environment variables.

We are using following simplified command to start in dev mode:

./gradlew :project-a:quarkusDev  :project-b:quarkusDev --parallel --console=plain

In our build.gradle files we have following content, used environment variables differ for each project:

quarkusDev {
    doFirst {
        if (providers.environmentVariable('PROJECT_A_DEBUG_PORT').isPresent()) {
           System.setProperty("debug", providers.environmentVariable('PROJECT_A_DEBUG_PORT').get())
        }
        if (providers.environmentVariable('PROJECT_A_QUARKUS_PROFILE').isPresent()) {
           System.setProperty("quarkus.profile", providers.environmentVariable('PROJECT_A_QUARKUS_PROFILE').get())
        }
    }
}

The problem: by setting the system properties like this causes other projects to sometimes use the system property of another project when started in parallel. This is probably due to the system property is being set for whole gradle process and not only for forked vms.

For quarkus profile we found that we could pass it via jvmArgs:

quarkusDev {
    def quarkusProfile = providers.environmentVariable('PROJECT_A_QUARKUS_PROFILE').getOrElse("dev")
    jvmArgs = ["-Dquarkus.profile=${quarkusProfile}"]
}

However, this does not work with the debug property, because the debug value is directly read from System.getProperty("debug") https://github.com/quarkusio/quarkus/blob/main/devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/tasks/QuarkusDev.java#L420

Is there another way to pass system properties only to quarkusDev task so it also works for debug?

For spring it seems possible to set system properties only for bootRun task according to following issue (spring-projects/spring-boot#23578) :

bootRun {
    systemProperty 'name', 'value'
}

Is there something similar for quarkusDev? Or is there a better way to solve this problem?

[quarkus-bot[bot]]

/cc @glefloch, @quarkusio/devtools