given:
        Task a = task("a", type: AsyncWithOutputDirectory)
        _ * a.outputDirectory >> file("outputDir")
        Task b = task("b", type: AsyncWithOutputDirectory)
        _ * b.outputDirectory >> file("outputDir").file("outputSubdir").file("output")

        expect:
        tasksAreNotExecutedInParallel(a, b)
    }

| `@link:{javadocPath}/org/gradle/api/tasks/OutputFile.html[OutputFile]`
| `File`*
| A single output file (not directory)

| `@link:{javadocPath}/org/gradle/api/tasks/OutputDirectory.html[OutputDirectory]`
| `File`*
| A single output directory (not file)

| `@link:{javadocPath}/org/gradle/api/tasks/OutputFiles.html[OutputFiles]`
| `Map<String, File>`+++**+++ or `Iterable<File>`+++*+++

                        "resources-project-builder",
                        "reporting-interpolation",
                        "target",
                        "site")),
                pom.getValue("reporting/outputDirectory"));
    }

    @Test
    void testPluginOrder() throws Exception {
        PomTestWrapper pom = buildPom("plugin-order");

import org.gradle.api.tasks.Internal
import org.gradle.api.tasks.LocalState
import org.gradle.api.tasks.Nested
import org.gradle.api.tasks.Optional
import org.gradle.api.tasks.OutputDirectories
import org.gradle.api.tasks.OutputDirectory
import org.gradle.api.tasks.OutputFile
import org.gradle.build.event.BuildEventsListenerRegistry
import org.gradle.integtests.fixtures.AbstractIntegrationSpec

        output.contains("Appending input file fingerprints for 'inputArtifactDependencies' to build cache key:")
        output.contains("Appending output property name to build cache key: outputDirectory")
        output.contains("Appending output property name to build cache key: resultsFile")
        output.contains("Build cache key for MakeGreen")
    }

+
Prefer using separate properties with `@OutputFile`/`@OutputDirectory` annotations or use `Map` properties with `@OutputFiles`/`@OutputDirectories` instead.