This chapter provides the information you need to migrate your Gradle 8.x builds to the latest Gradle release. For migrating from Gradle 4.x, 5.x, 6.x, or 7.x, see the older migration guide first.

We recommend the following steps for all users:

  1. Try running gradle help --scan and view the deprecations view of the generated build scan.

    Deprecations View of a Gradle Build Scan

    This is so you can see any deprecation warnings that apply to your build.

    Alternatively, you could run gradle help --warning-mode=all to see the deprecations in the console, though it may not report as much detailed information.

  2. Update your plugins.

    Some plugins will break with this new version of Gradle, for example because they use internal APIs that have been removed or changed. The previous step will help you identify potential problems by issuing deprecation warnings when a plugin does try to use a deprecated part of the API.

  3. Run gradle wrapper --gradle-version 8.1.1 to update the project to 8.1.1.

  4. Try to run the project and debug any errors using the Troubleshooting Guide.

Upgrading from 8.0 and earlier

CACHEDIR.TAG files are created in global cache directories

Gradle now emits a CACHEDIR.TAG file in some global cache directories, as specified in directory_layout.html.

This may cause these directories to no longer be searched or backed up by some tools. To disable it, use the following code in an init script in the Gradle user home directory:

init.gradle.kts
beforeSettings {
    caches {
        // Disable cache marking for all caches
        markingStrategy.set(MarkingStrategy.NONE)
    }
}
init.gradle
beforeSettings { settings ->
    settings.caches {
        // Disable cache marking for all caches
        markingStrategy = MarkingStrategy.NONE
    }
}

Configuration cache options renamed

In this release, the configuration cache feature was promoted from incubating to stable, and as such, all properties originally mentioned in the feature documentation (which had an unsafe part in their names, e.g. org.gradle.unsafe.configuration-cache) were renamed, in some cases, by just removing the unsafe bit.

Incubating property Finalized property

org.gradle.unsafe.configuration-cache

org.gradle.configuration-cache

org.gradle.unsafe.configuration-cache-problems

org.gradle.configuration-cache.problems*

org.gradle.unsafe.configuration-cache.max-problems

org.gradle.configuration-cache.max-problems

Note that the original org.gradle.unsafe.configuration-cache…​ properties continue to be honored in this release, and no warnings will be produced if they are used, but they will be deprecated and removed in a future release.

Potential breaking changes

Kotlin DSL scripts emit compilation warnings

Compilation warnings from Kotlin DSL scripts are printed to the console output. For example, the use of deprecated APIs in Kotlin DSL will emit warnings each time the script is compiled.

This is a potentially breaking change if you are consuming the console output of Gradle builds.

Configuring Kotlin compiler options with the kotlin-dsl plugin applied

If you are configuring custom Kotlin compiler options on a project with the kotlin-dsl plugin applied you might encounter a breaking change.

In previous Gradle versions, the kotlin-dsl plugin was adding required compiler arguments on afterEvaluate {}. Now that the Kotlin Gradle Plugin provides lazy configuration properties, our kotlin-dsl plugin switched to adding required compiler arguments to the lazy properties directly. As a consequence, if you were setting freeCompilerArgs the kotlin-dsl plugin is now failing the build because its required compiler arguments are overridden by your configuration.

build.gradle.kts
plugins {
    `kotlin-dsl`
}

tasks.withType(KotlinCompile::class).configureEach {
    kotlinOptions { // Deprecated non-lazy configuration options
        freeCompilerArgs = listOf("-Xcontext-receivers")
    }
}

With the configuration above you would get the following build failure:

* What went wrong
Execution failed for task ':compileKotlin'.
> Kotlin compiler arguments of task ':compileKotlin' do not work for the `kotlin-dsl` plugin. The 'freeCompilerArgs' property has been reassigned. It must instead be appended to. Please use 'freeCompilerArgs.addAll(\"your\", \"args\")' to fix this.

You must change this to adding your custom compiler arguments to the lazy configuration properties of the Kotlin Gradle Plugin in order for them to be appended to the ones required by the kotlin-dsl plugin:

build.gradle.kts
plugins {
    `kotlin-dsl`
}

tasks.withType(KotlinCompile::class).configureEach {
    compilerOptions { // New lazy configuration options
        freeCompilerArgs.addAll("-Xcontext-receivers")
    }
}

If you were already adding to freeCompilerArgs instead of setting its value, then you should not experience a build failure.

New API introduced may clash with existing Gradle DSL code

When a new property or method is added to an existing type in the Gradle DSL, it may clash with names already in use in user code.

When a name clash occurs, one solution is to rename the element in user code.

This is a non-exhaustive list of API additions in 8.1 that may cause name collisions with existing user code.

Using unsupported API to start external processes at configuration time is no longer allowed with the configuration cache enabled

Since Gradle 7.5, using Project.exec, Project.javaexec, and standard Java and Groovy APIs to run external processes at configuration time has been considered an error only if the feature preview STABLE_CONFIGURATION_CACHE was enabled. With the configuration cache promotion to a stable feature in Gradle 8.1, this error is detected regardless of the feature preview status. The configuration cache chapter has more details to help with the migration to the new provider-based APIs to execute external processes at configuration time.

Builds that do not use the configuration cache, or only start external processes at execution time are not affected by this change.

Deprecations

Mutating core plugin configuration usage

The allowed usage of a configuration should be immutable after creation. Mutating the allowed usage on a configuration created by a Gradle core plugin is deprecated. This includes calling any of the following Configuration methods:

  • setCanBeConsumed(boolean)

  • setCanBeResolved(boolean)

These methods now emit deprecation warnings on these configurations, except for certain special cases which make allowances for the existing behavior of popular plugins. This rule does not yet apply to detached configurations or configurations created in buildscripts and third-party plugins. Calling setCanBeConsumed(false) on apiElements or runtimeElements is not yet deprecated in order to avoid warnings that would be otherwise emitted when using select popular third-party plugins.

This change is part of a larger ongoing effort to make the intended behavior of configurations more consistent and predictable, and to unlock further speed and memory improvements in this area of Gradle.

The ability to change the allowed usage of a configuration after creation will be removed in Gradle 9.0.

Calling select methods on the JavaPluginExtension without the java component present

Starting in Gradle 8.1, calling any of the following methods on JavaPluginExtension without the presence of the default java component is deprecated:

  • withJavadocJar()

  • withSourcesJar()

  • consistentResolution(Action)

This java component is added by the JavaPlugin, which is applied by any of the Gradle JVM plugins including:

  • java-library

  • application

  • groovy

  • scala

Starting in Gradle 9.0, calling any of the above listed methods without the presence of the default java component will become an error.

WarPlugin#configureConfiguration(ConfigurationContainer)

Starting in Gradle 8.1, calling WarPlugin#configureConfiguration(ConfigurationContainer) is deprecated. This method was intended for internal use and was never intended to be used as part of the public interface.

Starting in Gradle 9.0, this method will be removed without replacement.

Relying on conventions for custom Test tasks

By default, when applying the java plugin, the testClassesDirs and classpath of all Test tasks have the same convention. Unless otherwise changed, the default behavior is to execute the tests from the default test TestSuite by configuring the task with the classpath and testClassesDirs from the test suite. This behavior will be removed in Gradle 9.0.

While this existing default behavior is correct for the use case of executing the default unit test suite under a different environment, it does not support the use case of executing an entirely separate set of tests.

If you wish to continue including these tests, use the following code to avoid the deprecation warning in 8.1 and prepare for the behavior change in 9.0. Alternatively, consider migrating to test suites.

build.gradle.kts
val test by testing.suites.existing(JvmTestSuite::class)
tasks.named<Test>("myTestTask") {
    testClassesDirs = files(test.map { it.sources.output.classesDirs })
    classpath = files(test.map { it.sources.runtimeClasspath })
}
build.gradle
tasks.myTestTask {
    testClassesDirs = testing.suites.test.sources.output.classesDirs
    classpath = testing.suites.test.sources.runtimeClasspath
}

Modifying Gradle Module Metadata after a publication has been populated

Altering the GMM (e.g., changing a component configuration variants) after a Maven or Ivy publication has been populated from their components is now deprecated. This feature will be removed in Gradle 9.0.

Eager population of the publication can happen if the following methods are called:

Previously, the following code did not generate warnings, but it created inconsistencies between published artifacts:

build.gradle.kts
publishing {
    publications {
        create<MavenPublication>("maven") {
            from(components["java"])
        }
        create<IvyPublication>("ivy") {
            from(components["java"])
        }
    }
}

// These calls eagerly populate the Maven and Ivy publications

(publishing.publications["maven"] as MavenPublication).artifacts
(publishing.publications["ivy"] as IvyPublication).artifacts

val javaComponent = components["java"] as AdhocComponentWithVariants
javaComponent.withVariantsFromConfiguration(configurations["apiElements"]) { skip() }
javaComponent.withVariantsFromConfiguration(configurations["runtimeElements"]) { skip() }
build.gradle
publishing {
    publications {
        maven(MavenPublication) {
            from components.java
        }
        ivy(IvyPublication) {
            from components.java
        }
    }
}

// These calls eagerly populate the Maven and Ivy publications

publishing.publications.maven.artifacts
publishing.publications.ivy.artifacts

components.java.withVariantsFromConfiguration(configurations.apiElements) { skip() }
components.java.withVariantsFromConfiguration(configurations.runtimeElements) { skip() }

In this example, the Maven and Ivy publications will contain the main JAR artifacts for the project, whereas the GMM module file will omit them.

Running tests on JVM versions 6 and 7

Running JVM tests on JVM versions older than 8 is deprecated. Testing on these versions will become an error in Gradle 9.0

Applying Kotlin DSL precompiled scripts published with Gradle < 6.0

Applying Kotlin DSL precompiled scripts published with Gradle < 6.0 is deprecated. Please use a version of the plugin published with Gradle >= 6.0.

Applying the kotlin-dsl together with Kotlin Gradle Plugin < 1.8.0

Applying the kotlin-dsl together with Kotlin Gradle Plugin < 1.8.0 is deprecated. Please let Gradle control the version of kotlin-dsl by removing any explicit kotlin-dsl version constraints from your build logic. This will let the kotlin-dsl plugin decide which version of the Kotlin Gradle Plugin to use. If you explicitly declare which version of the Kotlin Gradle Plugin to use for your build logic, update it to >= 1.8.0.

Accessing libraries or bundles from dependency version catalogs in the plugins {} block of a Kotlin script

Accessing libraries or bundles from dependency version catalogs in the plugins {} block of a Kotlin script is deprecated. Please only use versions or plugins from dependency version catalogs in the plugins {} block.

Using ValidatePlugins task without a Java Toolchain

Using a task of type ValidatePlugins without applying the Java Toolchains plugin is deprecated, and will become an error in Gradle 9.0.

To avoid this warning, please apply the plugin to your project:

build.gradle.kts
plugins {
    id("jdk-toolchains")
}
build.gradle
plugins {
    id 'jdk-toolchains'
}

The Java Toolchains plugin is applied automatically by the Java plugin, so you can also apply it to your project and it will fix the warning.

Deprecated members of the org.gradle.util package now report their deprecation

These members will be removed in Gradle 9.0.

  • WrapUtil.toDomainObjectSet(…​)

  • GUtil.toCamelCase(…​)

  • GUtil.toLowerCase(…​)

  • ConfigureUtil.configureByMap(…​)

Deprecated JVM vendor IBM Semeru

The enum constant JvmVendorSpec.IBM_SEMERU is now deprecated and will be removed in Gradle 9.0.

Please replace it by its equivalent JvmVendorSpec.IBM to avoid warnings and potential errors in the next major version release.

Setting custom build layout on StartParameter and GradleBuild

Following the related previous deprecation of the behaviour in Gradle 7.1, it is now also deprecated to use related StartParameter and GradleBuild properties. These properties will be removed in Gradle 9.0.

Setting custom build file using buildFile property in GradleBuild task has been deprecated.

Please use the dir property instead to specify the root of the nested build. Alternatively, consider using one of the recommended alternatives for GradleBuild task as suggested in Avoid using the GradleBuild task type section.

Setting custom build layout using StartParameter methods setBuildFile(File) and setSettingsFile(File) as well as the counterpart getters getBuildFile() and getSettingsFile() have been deprecated.

Please use standard locations for settings and build files:

  • settings file in the root of the build

  • build file in the root of each subproject

Deprecated org.gradle.cache.cleanup property

The org.gradle.cache.cleanup property in gradle.properties under Gradle user home has been deprecated. Please use the cache cleanup DSL instead to disable or modify the cleanup configuration.

Since the org.gradle.cache.cleanup property may still be needed for older versions of Gradle, this property may still be present and no deprecation warnings will be printed as long as it is also configured via the DSL. The DSL value will always take preference over the org.gradle.cache.cleanup property. If the desired configuration is to disable cleanup for older versions of Gradle (using org.gradle.cache.cleanup), but to enable cleanup with the default values for Gradle versions at or above Gradle 8, then cleanup should be configured to use Cleanup.DEFAULT:

cache-settings.gradle
if (GradleVersion.current() >= GradleVersion.version('8.0')) {
    apply from: "gradle8/cache-settings.gradle"
}
cache-settings.gradle.kts
if (GradleVersion.current() >= GradleVersion.version("8.0")) {
    apply(from = "gradle8/cache-settings.gradle")
}
gradle8/cache-settings.gradle
beforeSettings { settings ->
    settings.caches {
        cleanup = Cleanup.DEFAULT
    }
}
gradle8/cache-settings.gradle.kts
beforeSettings {
    caches {
        cleanup.set(Cleanup.DEFAULT)
    }
}

Deprecated using relative paths to specify Java executables

Using relative file paths to point to Java executables is now deprecated and will become an error in Gradle 9. This is done to reduce confusion about what such relative paths should resolve against.

Calling Task.getConvention(), Task.getExtensions() from a task action

Calling Task.getConvention(), Task.getExtensions() from a task action at execution time is now deprecated and will be made an error in Gradle 9.0.

See the configuration cache chapter for details on how to migrate these usages to APIs that are supported by the configuration cache.

Changes in the IDE integration

Workaround for false positive errors shown in Kotlin DSL plugins {} block using version catalog is not needed anymore

Version catalog accessors for plugin aliases in the plugins {} block aren’t shown as errors in IntelliJ IDEA and Android Studio Kotlin script editor anymore.

If you were using the @Suppress("DSL_SCOPE_VIOLATION") annotation as a workaround, you can now remove it.

If you were using the Gradle Libs Error Suppressor IntelliJ IDEA plugin, you can now uninstall it.

After upgrading Gradle to 8.1 you will need to clear the IDE caches and restart.

Also see the deprecated usages of version catalogs in the Kotlin DSL plugins {} block above.