The DefaultSourceDirectorySet constructor has been deprecated. How to use the ObjectFactory service?

Question

I recently updated to gradle version 5.0-rc-4, and when running ./gradlew assemble (or any other task) I now get the following message:

Deprecated Gradle features were used in this build, making it incompatible with Gradle 6.0.
Use '--warning-mode all' to show the individual deprecation warnings.

When I use ./gradlew assemble --warning-mode all I get:

> Configure project :
The DefaultSourceDirectorySet constructor has been deprecated. This is scheduled to be removed in Gradle 6.0. Please use the ObjectFactory service to create instances of SourceDirectorySet instead.

But in the following build.gradle I don't see where I'm using any DefaultSourceDirectorySet, so what is this warning about, and what would I need to change to be compatible with Gradle 6.0?

plugins {
    id 'org.jetbrains.kotlin.jvm' version '1.3.10'
}

dependencies {
    compile 'org.jetbrains.kotlin:kotlin-stdlib-jdk8'
}

repositories {
    mavenCentral()
    mavenLocal()
    jcenter()
}

Related

I found create version.txt file in project dir via build.gradle task(gradle 5.0) but I don't have constructs like that so I don't know how it would apply.

I found this deprecation mentioned in the release notes at https://docs.gradle.org/5.0-milestone-1/release-notes.html but they say

In this release of Gradle, the ObjectFactory service, which is part of the public API, now includes a method to create SourceDirectorySet instances. Plugins can now use this method instead of the internal types.

but I don't see how.

I also found the SourceDirectorySet interface at https://docs.gradle.org/current/javadoc/org/gradle/api/file/SourceDirectorySet.html but I don't see how to use it.

Template repository: https://github.com/PHPirates/kotlin-template-project

Answer 1

Update 2019-01-23 Five minutes ago, kotlin 1.3.20 was released and also updated in the Gradle repository so this issue should be solved by updating the Kotlin Gradle plugin to 1.3.20.

Update 2019-01-11 The target version in Youtrack issue KT-26808 has just been updated to 1.3.20. You can view the latest released version in the Gradle repositories here, but at the moment there are still a lot of open issues for 1.3.20.

Update 2018-12-17 The deprecation warning is fixed in commit https://github.com/JetBrains/kotlin/commit/67e82a54e5ee529116e881953f93a4c8f216e33a, the Youtrack issue is closed. Now waiting for a release to roll out.

As @Javaru pointed out, this has already been reported (in september 2018) at Youtrack issue KT-26808.

Using information from Lance's comment in the link that Thomas David Baker pointed to:

Answer:

If you get this warning while you are not using DefaultSourceDirectorySet directly, this is probably coming from a Gradle plugin you use. You could check this using the --warning-mode all --stacktrace flags for the Gradle build, so like ./gradlew assemble --warning-mode all --stacktrace.

In this particular case it's the Kotlin Gradle Plugin, they use it at DefaultKotlinSourceSet.kt#L140-L155:

private val createDefaultSourceDirectorySet: (name: String?, resolver: FileResolver?) -> SourceDirectorySet = run {
    val klass = DefaultSourceDirectorySet::class.java
    val defaultConstructor = klass.constructorOrNull(String::class.java, FileResolver::class.java)

    if (defaultConstructor != null && defaultConstructor.getAnnotation(java.lang.Deprecated::class.java) == null) {
        // TODO: drop when gradle < 2.12 are obsolete
        { name, resolver -> defaultConstructor.newInstance(name, resolver) }
    } else {
        // (code omitted)
    }
}

We can trust that they will resolve the issue in time, so don't worry about the warning.