Unsupported method: TaskOperationDescriptor.getDependencies() with Gradle 6.8

[Vampire]

The docs of TaskOperationDescriptor.getDependencies() say that this will happen if a Gradle version < 5.1 is targeted as there the capability was added.
But it happens with Gradle 6.8.
I didn't try this before, but I assume this used to work, thus reporting it as regression.

[Vampire]

And the same for getOriginPlugin

[ljacomet]

@Vampire Can you describe what you are trying to achieve? And which Gradle versions are in play.

[Vampire]

Only 6.8 and no specific goal.
I just played with getting a build as configuration cache safe as possible and thus needed to replace some code that was done at configuration time and needs to be done on every build with a build service that is registered as completion listener.
And in the listener I played with what info you get from the event.

To reproduce (sorry for the bad report before) just have this build.gradle.kts:

import org.gradle.kotlin.dsl.support.serviceOf
import org.gradle.tooling.events.FinishEvent
import org.gradle.tooling.events.OperationCompletionListener
import org.gradle.tooling.events.task.TaskOperationDescriptor

abstract class FooService : BuildService<BuildServiceParameters.None>, OperationCompletionListener {
    override fun onFinish(event: FinishEvent?) {
        val descriptor = event?.descriptor as? TaskOperationDescriptor
        println("event?.descriptor?.dependencies = ${descriptor?.dependencies}")
        println("event?.descriptor?.originPlugin = ${descriptor?.originPlugin}")
    }
}

serviceOf<BuildEventsListenerRegistry>()
    .onTaskCompletion(
        serviceOf<BuildServiceRegistry>()
            .registerIfAbsent("foo", FooService::class) { }
    )

and then execute the help task

[big-guy]

This also happens in 6.7.

It looks like this is something unfinished. The TODO here is saying a lot:

gradle/subprojects/build-events/src/main/java/org/gradle/internal/build/event/DefaultBuildEventsListenerRegistry.java

Line 226 in c20e0c8

// TODO - reuse adapters from tooling api client

The event types are shared with TAPI, but the conversion is done in a different way and some information isn't available/lost.

@eskatos I'm guessing this is something low priority/only added to as we need something for CC.

[eugene-krivobokov]

@Vampire Can you describe what you are trying to achieve? And which Gradle versions are in play.

I'd like to add my similar use case.
I'm trying to calculate a critical path (#13931). To do so I need to know dependencies between tasks.

Didn't find a better workaround than resolving them in org.gradle.api.execution.TaskExecutionListener.afterExecute. You can take a look at this naive implementation here: avito-tech/avito-android#973
But in this case, I'm facing other bugs: https://issuetracker.google.com/issues/142268503, https://issuetracker.google.com/issues/188457864

Maybe you can point on a correct way to find all predecessors of a task.

[robercoding]

Issue still happens to this day with 7.5.1 gradle version. I'm assuming it's not expected to work, right? Is there a known alternative?