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//
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//
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// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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[[upgrading_version_9]]

= Upgrading within Gradle 9.x.y

This chapter provides the information you need to migrate your Gradle 9.x.y builds to the latest.
For migrating to Gradle 9.0.0, see the <<upgrading_major_version_9.adoc#upgrading_major_version_9, older migration guide>> first.

We recommend the following steps for all users:

. Try running `gradle help --scan` and view the https://docs.gradle.com/develocity/get-started/#identifying_deprecated_gradle_functionality[deprecations view] of the generated Build Scan.
+
image::deprecations.png[Deprecations View of a Gradle Build Scan]
+
This lets you see any deprecation warnings that apply to your build.
+
Alternatively, you can run `gradle help --warning-mode=all` to see the deprecations in the console, though it may not report as much detailed information.
. Update your plugins.
+
Some plugins will break with this new version of Gradle 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 tries to use a deprecated part of the API.
+
. Run `gradle wrapper --gradle-version {gradleVersion}` to update the project to {gradleVersion}.
. Try to run the project and debug any errors using the <<troubleshooting.adoc#troubleshooting, Troubleshooting Guide>>.

[[changes_9.4.0]]
== Upgrading from 9.3.0 and earlier

=== Potential breaking changes

==== The `java-gradle-plugin` plugin now adds the `gradleApi()` dependency to the `compileOnlyApi` scope

The dependency on `gradleApi()` added by the `java-gradle-plugin` will be added to the `compileOnlyApi` scope instead of `api`.

For most plugin projects, this change should be transparent and without any side effects.

==== Stricter validation for published plugins

For plugin builds that apply any of the `com.gradle.plugin-publish`, `ivy-publish`, or `maven-publish` plugins, Gradle now automatically enables stricter validation of plugin code.

In order not to break your builds, this does not apply to local plugins (in `buildSrc` or included builds containing build logic).
However, we encourage you to always enable stricter validation:

.build.gradle.kts
[source,kotlin]
----
tasks.validatePlugins {
    enableStricterValidation = true
}
----


==== CodeNarc compilation classpath is set by default

Some of the rulesets included with CodeNarc make use of link:https://codenarc.org/codenarc-enhanced-classpath-rules.html[enhanced classpath rules], which require additional dependencies to be present on the CodeNarc task's compilation classpath.
Previously, this had to be configured explicitly, but the CodeNarc plugin now adds the compile classpath of a source set to its CodeNarc task `compilationClasspath` by default.
If your build relies on a custom configuration for the `compilationClasspath` of a CodeNarc task, you will need to continue explicitly setting it to override the new default behavior.

A side effect of this change is that there is now a task dependency between the CodeNarc task and the associated source set's compile task.
Previously, these tasks could run in parallel, but now the CodeNarc task will wait for the compile task to complete first so that it can add the compiled classes to its classpath.
In some cases, this may lead to longer build times if CodeNarc tasks were previously running in parallel with compile tasks.
If you are not using any enhanced classpath rules, you can avoid this task dependency by setting an empty `compilationClasspath` for the CodeNarc task:

.build.gradle.kts
[source,kotlin]
----
plugins {
    id("groovy")
    id("codenarc")
}

tasks.withType<CodeNarc>().configureEach {
    // Override the default compilation classpath
    compilationClasspath = files()
}
----

==== Upgrade to Kotlin 2.3.0

The embedded Kotlin has been upgraded from 2.2.21 to link:https://github.com/JetBrains/kotlin/releases/tag/v2.3.0[Kotlin 2.3.0].

==== Upgrade to Zinc 1.12.0

Zinc has been updated to https://github.com/sbt/zinc/releases/tag/v1.12.0[1.12.0].

=== Deprecations

[[findAll_removal]]
==== Deprecation of `DomainObjectCollection.findAll(Closure)`

`DomainObjectCollection.findAll(Closure)` has been deprecated. This API relies on a Groovy type and eagerly evaluates the contents of the container.

This API will be removed in Gradle 10 with no direct replacement.
`DomainObjectCollection.matching(Spec)` is a similar API for selecting elements without evaluating the contents of the container immediately.

[[deprecate_apply_false_in_precompiled_script_plugins]]
==== Deprecation of `apply false` in precompiled script plugins
The use of `apply false` in <<implementing_gradle_plugins_precompiled.adoc#implementing_precompiled_plugins, precompiled script plugins>> has been deprecated and will become an error in Gradle 10.0.0.

Using `apply false` does not have any effect in precompiled script plugins (the plugin is still applied), and it can lead to confusion for users who expect it to prevent the plugin from being applied.
Plugins used in precompiled script plugins are already available on the classpath, so using `apply false` would do nothing.

To fix this deprecation, remove the plugin declaration from the precompiled script plugin:
.my-plugin.gradle.kts
[source,kotlin]
----
plugins {
    // Delete the following line to remove the deprecation warning:
    id("org.gradle.test-retry") apply false
    // The plugin will still be on the classpath, but it will not be applied as part of this precompiled script plugin.
}
----

[[changes_9.3.0]]
== Upgrading from 9.2.0 and earlier

=== Potential breaking changes

==== TestNG output may change when using versions before 6.9.13.3

As part of the `AbstractTestTask` refactoring, Gradle’s integration with TestNG has been updated.
Gradle now relies on a correctly functioning `IClassListener` to report the hierarchy of test classes and methods.

When using TestNG versions **earlier than 6.9.13.3**, this can lead to different or degraded output:

- With older versions, class information may be lost. For example, output that previously looked like: `org.gradle > TestClass > ok` may now be reported simply as: `ok`.
- For TestNG versions **from 6.9.10 up to (but not including) 6.9.13.3**, the `IClassListener` API exists but is broken. This can result in even worse output, such as empty or missing names.

To get correct and stable output, we recommend upgrading to **TestNG 6.9.13.3 or newer**.

==== Upgrade to Kotlin 2.2.21

The embedded Kotlin has been upgraded from 2.2.20 to link:https://github.com/JetBrains/kotlin/releases/tag/v2.2.21[2.2.21].

==== Upgrade to Jansi 2.4.2

Jansi was upgraded from https://github.com/fusesource/jansi/blob/jansi-2.4.2/changelog.md#jansi-118-released-2019-04-02[1.18] to https://github.com/fusesource/jansi/releases/tag/jansi-2.4.2[2.4.2] to pick up support for Windows ARM64.

==== Upgrade to ASM 9.9

ASM was upgraded from 9.8 to https://asm.ow2.io/versions.html[9.9] to ensure earlier compatibility for Java 26.

==== Upgrade to Groovy 4.0.29

Groovy has been updated to https://groovy-lang.org/changelogs/changelog-4.0.29.html[4.0.29].

==== Upgrade to JaCoCo 0.8.14

JaCoCo has been updated to https://www.jacoco.org/jacoco/trunk/doc/changes.html[0.8.14].

=== Deprecations

[[deprecated_wrapper_get_available_distribution_types]]
==== Deprecation of the `Wrapper.getAvailableDistributionTypes()` method

The method on the link:{javadocPath}/org/gradle/api/tasks/wrapper/Wrapper.html[Wrapper] task has been deprecated and will be removed in Gradle 10.

Use link:{javadocPath}/org/gradle/api/tasks/wrapper/Wrapper.DistributionType.html#values()[`Wrapper.DistributionType.values()`] to obtain the available distribution types instead.

[[publishing_dependency_on_unpublished_project]]
==== Deprecation of publishing dependencies on unpublished projects

When publishing a project, Gradle resolves project dependencies to the coordinates of the target project's publication.
If the target project has no publication, Gradle currently resolves the dependency silently using that project's `group`, `name`, and `version`.

Starting with Gradle 10, this behavior is deprecated.
Gradle will no longer silently ignore the absence of a publication.
Publishing a project that depends on another project without a publication will be forbidden and will cause the build to fail.
This change prevents publishing broken metadata with dependency coordinates that cannot be resolved.

The example below demonstrates a build that triggers the deprecated behavior:

.build.gradle.kts
[source,kotlin]
----
plugins {
    id("java-library")
    id("maven-publish")
}

group = "com.example"
version = "1.0.0"

dependencies {
    api(project(":other"))
}

publishing {
    publications {
        create<MavenPublication>("maven") {
            from(components["java"])
        }
    }
}
----

.other/build.gradle.kts
[source,kotlin]
----
plugins {
    id("java-library")
}

group = "com.example"
version = "1.0.0"
----

To avoid this deprecation, ensure that all project dependencies of published projects are also published.
In the example above, applying the `maven-publish` plugin and configuring a publication in the `:other` project resolves the issue:

.other/build.gradle.kts
[source,kotlin]
----
plugins {
    id("java-library")
    id("maven-publish")
}

group = "com.example"
version = "1.0.0"

publishing {
    publications {
        create<MavenPublication>("maven") {
            from(components["java"])
        }
    }
}
----

[[deprecate_legacy_usage_values]]
==== Deprecation of legacy `Usage` attribute values

Since Gradle 5.6, the link:{javadocPath}/org/gradle/api/attributes/Usage.html[`Usage`] attribute has been split into an additional link:{javadocPath}/org/gradle/api/attributes/LibraryElements.html[`LibraryElements`] attribute.
In the JVM ecosystem, `Usage` indicates whether a variant is intended for compilation or runtime, while `LibraryElements` specifies the format of the artifact (for example, a JAR file or a classes directory).

To ease migration, Gradle has automatically mapped legacy `Usage` values to their corresponding `Usage` and `LibraryElements` pairs:

|===
| Legacy `Usage`           | Replaced `Usage` | Replaced `LibraryElements`
| `java-api-jars`          | `java-api`       | `jar`
| `java-api-classes`       | `java-api`       | `classes`
| `java-runtime-jars`      | `java-runtime`   | `jar`
| `java-runtime-classes`   | `java-runtime`   | `classes`
| `java-runtime-resources` | `java-runtime`   | `resources`
|===

Starting with Gradle 10, this automatic mapping will no longer occur when legacy `Usage` values are added directly to an `AttributeContainer` in build logic.
To maintain backward compatibility for already published modules, Gradle will continue translating legacy `Usage` values found in published Gradle Module Metadata.

[[module_identity_for_root_component]]
==== Deprecation of using module coordinates to depend on the current project

Starting with Gradle 10, declaring a dependency on the current project using module coordinates (`group`, `name`, `version`) will no longer resolve to that project.
Instead, Gradle will attempt to resolve that dependency from a repository.

The example below demonstrates the change in behavior:

.my-project/build.gradle.kts
[source,kotlin]
----
group = "com.example"
version = "1.0.0"

val deps = configurations.dependencyScope("deps")
val classpath = configurations.resolvable("classpath") {
    extendsFrom(deps.get())
    attributes.attribute(Category.CATEGORY_ATTRIBUTE, objects.named(Category.LIBRARY))
}

val elements = configurations.consumable("elements") {
    attributes.attribute(Category.CATEGORY_ATTRIBUTE, objects.named(Category.LIBRARY))
}

dependencies {
    // In Gradle 9.x, this dependency resolves to the `elements` configuration.
    // In Gradle 10, this dependency will attempt to resolve from a repository.
    deps("com.example:my-project:1.0.0")
}
----

To continue depending on the current project, use a `project` dependency:

.my-project/build.gradle.kts
[source,kotlin]
----
dependencies {
    // Declare a dependency on the current project to continue resolving
    // to the current project.
    deps(project)
}
----

[[changes_9.2.0]]
== Upgrading from 9.1.0 and earlier

=== Potential breaking changes

==== Upgrade to Kotlin 2.2.20

The embedded Kotlin has been upgraded from 2.2.0 to link:https://github.com/JetBrains/kotlin/releases/tag/v2.2.20[Kotlin 2.2.20].

==== Removed incubating `ObjectFactory#dependencyCollector()` method

The incubating `ObjectFactory#dependencyCollector()` method has been removed.
You can still create `DependencyCollectors` within Gradle <<properties_providers.adoc#managed_types, managed types>>.

==== Consumable configurations in bundled plugins are now initialized lazily

Consumable configurations created by bundled Gradle plugins are now initialized only when needed.
`Configure` actions on these configurations no longer run at configuration time by default.
They only execute if the configuration is published, consumed as a variant, or otherwise realized by build logic.

For example:

.build.gradle.kts
[source,kotlin]
----
plugins {
    id("java-library")
}

configurations.named("apiElements").configure {
    println("Configuring apiElements")
}
----

With this change, the `Configuring apiElements` line is no longer printed during configuration time unless `apiElements` is actually realized.

See <<declaring_configurations.adoc#declaring-dependency-configurations,Declaring Configurations>> for more guidance.

[[validate_plugins_java_version]]
==== `ValidatePlugins` now has stricter Java version requirements

The `ValidatePlugins` task must now run on a Java version that is supported by the Gradle daemon.
This change was made because the task depends on several core Gradle services, which may now be compiled to the same bytecode version supported by the daemon.

By default, the task’s convention has been updated:

* If your project’s toolchain is compatible, `ValidatePlugins` will use it.
* Otherwise, it will fall back to the Java version used to run Gradle.

If you explicitly set a toolchain like this:

[.multi-language-sample]
=====
.build.gradle.kts
[source,kotlin]
----
tasks.withType<ValidatePlugins>().configureEach {
    javaLauncher.set(
        project.javaToolchains.launcherFor {
            languageVersion.set(JavaLanguageVersion.of(17))
        }
    )
}
----
=====
[.multi-language-sample]
=====
.build.gradle
[source,groovy]
----
tasks.withType(ValidatePlugins).configureEach {
    javaLauncher.set(
        project.javaToolchains.launcherFor {
            languageVersion.set(JavaLanguageVersion.of(17))
        }
    )
}
----
=====

If the specified Java version is **not** compatible with the Gradle daemon, you must update it to a <<compatibility.adoc#java_runtime,compatible version>>.

=== Deprecations

[[project_container_methods]]
==== Deprecation of `Project.container(...)` methods

The link:{javadocPath}/org/gradle/api/Project.html#container-java.lang.Class-[`Project.container(...)`] methods are deprecated and will be removed in Gradle 10.
These methods manually create named domain object containers.

Use a <<properties_providers.adoc#mutable_managed_properties,managed property>> to let Gradle instantiate containers automatically.
If a managed property isn’t possible, use `ObjectFactory.domainObjectContainer(...)` (available since Gradle 5.5).
Unlike `Project.container(Class)`, the `ObjectFactory` version decorates container elements and makes them extension aware.

[[dependency_management_rules]]
==== Deprecation of ruleSource-based dependency management APIs

The link:{javadocPath}/org/gradle/model/RuleSource.html[`RuleSource`]-based dependency management APIs have been deprecated and will be removed in Gradle 10.0.0.

Deprecated APIs include:

- link:{javadocPath}/org/gradle/api/artifacts/dsl/ComponentMetadataHandler.html#all(java.lang.Object)[`ComponentMetadataHandler.all(Object)`]
- link:{javadocPath}/org/gradle/api/artifacts/dsl/ComponentMetadataHandler.html#all(java.lang.Object)[`ComponentMetadataHandler.withModule(Object,Object)`]
- link:{javadocPath}/org/gradle/api/artifacts/ComponentSelectionRules.html#all(java.lang.Object)[`ComponentSelectionRules.all(Object)`]
- link:{javadocPath}/org/gradle/api/artifacts/ComponentSelectionRules.html#withModule(java.lang.Object,java.lang.Object)[`ComponentSelectionRules.withModule(Object,Object)`]

Use the alternative methods that accept a `ComponentMetadataRule` class or an `Action`.

[[deprecate_register_feature_no_java_plugin]]
==== Deprecation of calling `registerFeature` without applying the Java plugin

Creating a JVM feature with link:{javadocPath}/org/gradle/api/plugins/JavaPluginExtension.html#registerFeature(java.lang.String,org.gradle.api.Action)[`JavaPluginExtension#registerFeature`] before applying the Java plugin has been deprecated and will become an error in Gradle 10.0.0.

Ensure the Java plugin is applied before invoking `registerFeature`.
The following bundled plugins apply the Java plugin automatically:

- `java-library`
- `application`
- `groovy`
- `scala`
- `war`

[[changes_9.1.0]]
== Upgrading from 9.0.0 and earlier

=== Potential breaking changes

==== Upgrade to ASM 9.8

ASM was upgraded from 9.7.1 to https://asm.ow2.io/versions.html[9.8] to ensure earlier compatibility for Java 25.

==== Upgrade to Groovy 4.0.28

Groovy has been updated to https://groovy-lang.org/changelogs/changelog-4.0.28.html[Groovy 4.0.28].

=== Deprecations

[[dependency_multi_string_notation]]
==== Deprecation of multi-string dependency notation

In an effort to simplify and standardize the Gradle API, the multi-string dependency notation used in dependency management has been deprecated and will no longer be permitted in Gradle 10.
Gradle will primarily accept dependency declarations in the form of a single string, with each dependency coordinate separated by a colon.

Below are examples of the deprecated multi-string notation:

====
[.multi-language-sample]
=====
.build.gradle.kts
[source,kotlin]
----
dependencies {
    implementation(group = "org", name = "foo", version = "1.0")
    implementation(group = "org", name = "foo", version = "1.0", configuration = "conf")
    implementation(group = "org", name = "foo", version = "1.0", classifier = "classifier")
    implementation(group = "org", name = "foo", version = "1.0", ext = "ext")
}

testing.suites.named<JvmTestSuite>("test") {
    dependencies {
        implementation(module(group = "org", name = "foo", version = "1.0"))
    }
}
----
=====
[.multi-language-sample]
=====
.build.gradle
[source,groovy]
----
dependencies {
    implementation(group: 'org', name: 'foo', version: '1.0')
    implementation(group: 'org', name: 'foo', version: '1.0', configuration: 'conf')
    implementation(group: 'org', name: 'foo', version: '1.0', classifier: 'classifier')
    implementation(group: 'org', name: 'foo', version: '1.0', ext: 'ext')
}

testing.suites.test {
    dependencies {
        implementation(module(group: 'org', name: 'foo', version: '1.0'))
    }
}
----
=====
====

These declarations should be replaced with the single-string notation:

====
[.multi-language-sample]
=====
.build.gradle.kts
[source,kotlin]
----
dependencies {
    implementation("org:foo:1.0")
    implementation("org:foo:1.0") {
        targetConfiguration = "conf"
    }
    implementation("org:foo:1.0:classifier")
    implementation("org:foo:1.0@ext")
}

testing.suites.named<JvmTestSuite>("test") {
    dependencies {
        implementation("org:foo:1.0")
    }
}
----
=====
[.multi-language-sample]
=====
.build.gradle
[source,groovy]
----
dependencies {
    implementation("org:foo:1.0")
    implementation("org:foo:1.0") {
        targetConfiguration = "conf"
    }
    implementation("org:foo:1.0:classifier")
    implementation("org:foo:1.0@ext")
}

testing.suites.test {
    dependencies {
        implementation("org:foo:1.0")
    }
}
----
=====
====

In some cases, a complete single-string notation may not be known up front.
Instead of concatenating the coordinates into a new string, it is possible to use a link:{javadocPath}/org/gradle/api/artifacts/dsl/DependencyFactory.html[`DependencyFactory`] to create `Dependency` instances directly from the individual components:

====
[.multi-language-sample]
=====
.build.gradle.kts
[source,kotlin]
----
val group = "org"
val artifactId = "foo"
val version = "1.0"

configurations.dependencyScope("implementation") {
    dependencies.add(project.dependencyFactory.create(group, artifactId, version))
}
----
=====
[.multi-language-sample]
=====
.build.gradle
[source,groovy]
----
def group = "org"
def artifactId = "foo"
def version = "1.0"

configurations.dependencyScope("implementation") {
    dependencies.add(project.dependencyFactory.create(group, artifactId, version))
}
----
=====
====

[[reporting_extension_file]]
==== Deprecation of `ReportingExtension.file(String)`

The link:{javadocPath}/org/gradle/api/reporting/ReportingExtension.html#file(String)[`file()` method] on `ReportingExtension` has been deprecated and will be removed in Gradle 10.0.0.

Instead, use `ReportingExtension.getBaseDirectory()` with `file(String)` or `dir(String)`.

[[reporting_extension_api_doc_title]]
==== Deprecation of `ReportingExtension.getApiDocTitle()`

The link:{javadocPath}/org/gradle/api/reporting/ReportingExtension.html#getApiDocTitle()[`getApiDocTitle()` method] on `ReportingExtension` has been deprecated and will be removed in Gradle 10.0.0.

There is no direct replacement for this method.

[[set-all-jvm-args]]
==== Deprecation of `JavaForkOptions.setAllJvmArgs()`

The link:{javadocPath}/org/gradle/process/JavaForkOptions.html#setAllJvmArgs(java.util.List)[`setAllJvmArgs()` method] on `JavaForkOptions` and, by inheritance, on `JavaExecSpec` has been deprecated and will be removed in Gradle 10.0.0.

Instead, to overwrite existing JVM arguments, use:

* `JavaForkOptions.jvmArgs()`
* `JavaForkOptions.setJvmArgs()`
* Provide a <<incremental_build.adoc#sec:task_input_nested_inputs,`CommandLineArgumentProvider`>> to add arguments via `JavaForkOptions.getJvmArgumentProviders()`

Note that link:{javadocPath}/org/gradle/process/JavaForkOptions.html#setAllJvmArgs(java.util.List)[`setAllJvmArgs()` method] on `JavaForkOptions` cleared all fork options before setting `jvmArgs`.
The properties cleared included:

* System properties configured via `JavaForkOptions.systemProperties`
* JVM argument providers configured via `JavaForkOptions.jvmArgumentProviders`
* Argument providers configured via `JavaExecSpec.argumentProviders`
* Memory settings configured via `JavaForkOptions.minHeapSize` and `JavaForkOptions.maxHeapSize`
* All other JVM arguments configured via `JavaForkOptions.jvmArgs`
* The assertion and debug flags configured via `JavaForkOptions.enableAssertions` and `JavaForkOptions.debug`

If the arguments you provide to `setJvmArgs()` or `jvmArgs()` depend on any of the above properties being cleared, you will need to manually clear them.

Consider the following snippets for examples of how to implement this change:

====
[.multi-language-sample]
=====
.build.gradle.kts
[source, kotlin]
----
plugins {
    id("java")
}

tasks.register<JavaExec>("myRunTask") {
    jvmArgumentProviders.clear() // Clear existing JVM argument providers
    maxHeapSize = null // Clear max heap size
    jvmArgs = listOf("-Dfoo", "-Dbar") // Set new JVM arguments
}
----
=====
[.multi-language-sample]
=====
.build.gradle
[source, groovy]
----
plugins {
    id("java")
}

tasks.named('myRunTask', JavaExec) {
    jvmArgumentProviders.clear() // Clear existing JVM argument providers
    maxHeapSize = null // Clear max heap size
    jvmArgs = ["-Dfoo", "-Dbar"] // Set new JVM arguments
}
----
=====
====

[[archives-configuration]]
==== Deprecation of `archives` configuration

The `archives` configuration added by the <<base_plugin.adoc#base_plugin,`base` plugin>> has been deprecated and will be removed in Gradle 10.0.0.
Adding artifacts to the `archives` configuration will now result in a deprecation warning.

If you want the artifact to be built when running the `assemble` task, add the artifact (or the task that produces it) as a dependency on `assemble`:

.build.gradle.kts
[source,kotlin]
----
val specialJar = tasks.register<Jar>("specialJar") {
    archiveBaseName.set("special")
    from("build/special")
}

tasks.named("assemble") {
    dependsOn(specialJar)
}
----

[[deprecate-visible-property]]
==== Deprecation of the `Configuration.visible` property

Prior to Gradle 9.0.0, any configuration with `isVisible()` returning `true` would implicitly trigger artifact creation when running the `assemble` task.
This behavior was removed in Gradle 9.0.0, and the `Configuration.visible` property no longer has any effect.
The property is now deprecated and will be removed in Gradle 10.0.0.
You can safely remove any usage of `visible`.

If you want the artifacts of a configuration to be built when running the `assemble` task, add an explicit task dependency on `assemble`:

.build.gradle.kts
[source,kotlin]
----
val specialJar = tasks.register<Jar>("specialJar") {
    archiveBaseName.set("special")
    from("build/special")
}

configurations {
    consumable("special") {
        outgoing.artifact(specialJar)
    }
}

tasks.named("assemble") {
    dependsOn(specialJar)
}
----

[[deprecated-gradle-build-non-string-properties]]
==== Deprecation of non-string `projectProperties` in `GradleBuild` task

The `GradleBuild` task now deprecates using non-String values in `startParameter.projectProperties`.
While the type is declared as `Map<String, String>`, there was no strict enforcement, allowing non-String values to be set.
This deprecated behavior will be removed in Gradle 10.0.0.

If you are using non-String values in project properties, convert them to `String` representation:

====
[.multi-language-sample]
=====
.build.gradle.kts
[source,kotlin]
----
val myIntProp = 42

tasks.register<GradleBuild>("nestedBuild") {
    startParameter.projectProperties.put("myIntProp", "$myIntProp") // Convert int to String
}
----
=====
[.multi-language-sample]
=====
.build.gradle
[source,groovy]
----
def myIntProp = 42

tasks.register('nestedBuild', GradleBuild) {
    startParameter.projectProperties.put('myIntProp', "$myIntProp") // Convert int to String
}
----
=====
====

[[toolchain-project-properties]]
==== Deprecation of project properties for toolchain configuration

In previous versions of Gradle, you could configure toolchains using <<build_environment.adoc#sec:project_properties, project properties>> on the command line with the `-P` flag.
For example, to disable toolchain auto-detection, you could use `-Porg.gradle.java.installations.auto-detect=false`.
This behavior is deprecated and will be removed in Gradle 10.0.0.
Instead, you should specify these settings as <<build_environment.adoc#sec:gradle_configuration_properties, Gradle properties>> using the `-D` flag:

[source,text]
----
-Dorg.gradle.java.installations.auto-detect=false
----

