Capture execution time as custom value

build.gradle.kts

import com.gradle.develocity.agent.gradle.scan.BuildScanConfiguration
import org.gradle.api.internal.project.ProjectInternal
import org.gradle.api.services.BuildService
import org.gradle.api.services.BuildServiceParameters
import org.gradle.tooling.events.FinishEvent
import org.gradle.tooling.events.OperationCompletionListener
import java.time.Instant

object Capture {
    var startTime: Long = 0L
    var endTime: Long = 0L
}

abstract class BuildTimeService : BuildService<BuildServiceParameters.None>, AutoCloseable, OperationCompletionListener  {

    private val startTime : Long = Instant.now().toEpochMilli()

    override fun close() {
        Capture.startTime = startTime
        Capture.endTime = Instant.now().toEpochMilli()
    }

    override fun onFinish(ignored: FinishEvent){
        // ignored
    }

    fun processResults(api: BuildScanConfiguration) {
        println("startTime: ${Instant.ofEpochMilli(startTime)}")
        api.value("Duration", "${Instant.now().toEpochMilli() - startTime}ms")
    }
}

tasks.withType<JavaCompile> {
    doLast {
        Thread.sleep(3000)
    }
}

develocity {

    val buildTimeServiceProvider = gradle.sharedServices.registerIfAbsent("buildTimeService", BuildTimeService::class.java) {}

    // We register a BuildEventsListenerRegistry in order to mark the BuildService as configuration cache compatible but is otherwise unused.
    (project as ProjectInternal).services.get(BuildEventsListenerRegistry::class.java).onTaskCompletion(buildTimeServiceProvider)

    buildScan {
        Thread.sleep(3000)

        buildFinished {
            println("Start Time: ${Instant.ofEpochMilli(Capture.startTime)}")
            println("End Time: ${Instant.ofEpochMilli(Capture.endTime)}")
            buildScan.value("Duration", "${Capture.endTime - Capture.startTime}ms")
        }
    }
}