Add support for Android Gradle plugin 9.0

[IsakTheHacker]

When running Gradle with the --warning-mode all option, you will get a deprecation warning from the Chaquopy Gradle plugin:

The org.gradle.util.VersionNumber type has been deprecated. This is scheduled to be removed in Gradle 9.0. Consult the upgrading guide for further information: https://docs.gradle.org/8.6/userguide/upgrading_version_8.html#org_gradle_util_reports_deprecations

This probably comes from the checkAgpVersion function from this file:

fun checkAgpVersion() {
    val version = VersionNumber.parse(
        findPlugin("com.android.tools.build", "gradle").version)
    val minVersion = VersionNumber.parse(Common.MIN_AGP_VERSION)
    if (version < minVersion) {
        throw GradleException(
            "This version of Chaquopy requires Android Gradle plugin version " +
            "$minVersion or later. Please edit the version of " +
            "com.android.application, com.android.library or " +
            "com.android.tools.build:gradle in your top-level build.gradle " +
            "file. See https://chaquo.com/chaquopy/doc/current/versions.html.")
    }
}

[mhsmith]

Thanks for letting me know. Gradle 9.0 doesn't exist yet, so it probably won't be used by Android for at least another 2 Android Studio releases. And the warning isn't visible by default, so this isn't urgent to fix.

• Related: VersionNumber replacement gradle/gradle#28755

[mhsmith]

Based on the version numbers in Google's Maven repository, they are finally moving to Gradle 9 now with AGP 9.0.

[mhsmith]

The full set of warnings from the demo app with Gradle 8.13:

> Configure project :app

• The org.gradle.api.plugins.Convention type has been deprecated. This is scheduled to be removed in Gradle 9.0. Consult the upgrading guide for further information: https://docs.gradle.org/8.13/userguide/upgrading_version_8.html#deprecated_access_to_conventions
  • -Dorg.gradle.deprecation.trace=true shows that this comes from the Kotlin plugin, not us.
• The org.gradle.util.VersionNumber type has been deprecated. This is scheduled to be removed in Gradle 9.0. Consult the upgrading guide for further information: https://docs.gradle.org/8.13/userguide/upgrading_version_7.html#org_gradle_util_reports_deprecations
  • Fixed.
• Mutating configuration container for buildscript of project ':app' using create(String) has been deprecated. This will fail with an error in Gradle 9.0. Consult the upgrading guide for further information: https://docs.gradle.org/8.13/userguide/upgrading_version_8.html#mutating_buildscript_configurations
  • Fixed.
• w: file:///Users/msmith/git/chaquo/chaquopy/demo/app/build.gradle.kts:56:9: 'resourceConfigurations: MutableSet' is deprecated. Support for resource configurations will be removed. For language resource configurations in applications, use androidResources.localeFilters.
  • Fixed.
• The Project.exec(Action) method has been deprecated. This is scheduled to be removed in Gradle 9.0. Use ExecOperations.exec(Action) or ProviderFactory.exec(Action) instead. Consult the upgrading guide for further information: https://docs.gradle.org/8.13/userguide/upgrading_version_8.html#deprecated_project_exec
  • Fixed.

> Task :app:extractDebugPythonBuildPackages

• Invocation of Task.project at execution time has been deprecated. This will fail with an error in Gradle 10.0. This API is incompatible with the configuration cache, which will become the only mode supported by Gradle in a future release. Consult the upgrading guide for further information: https://docs.gradle.org/8.13/userguide/upgrading_version_7.html#task_project
  • This would be a very disruptive change, so I won't do it until it's necessary. They first threatened to remove this in Gradle 8, then 9, and now 10, so who knows when it will actually happen.

[mhsmith]

After resolving these warnings, and running the AGP Upgrade Assistant in Android Studio Otter Canary 1, the project now syncs successfully with Gradle 9.0.0 and AGP 9.0.0-alpha06. It shows a lot of new warnings, but many of them are internal to AGP and likely to be fixed before the final release, so I won't pursue this any further yet.

This is their first major version increment in a long time, so there's a higher than normal chance of problems. However, it probably won't be released until late October or early November, whereas we want our next release to be as soon as possible after Python 3.14 comes out in early October. So test as thoroughly as possible with the latest pre-release possible.