Gradle plugin v2 with versioning plugin requires olderVersionsDir to exist

[jeffdgr8]

Describe the bug
With the Dokka Gradle plugin v2, using the versioning plugin and configuring olderVersionsDir to a directory path that doesn't currently exist, the task :dokkaGeneratePublicationHtml fails with the error:

A problem was found with the configuration of task ':dokkaGeneratePublicationHtml' (type 'DokkaGeneratePublicationTask').

• In plugin 'org.jetbrains.dokka.gradle.DokkaBasePlugin_Decorated' type 'org.jetbrains.dokka.gradle.tasks.DokkaGeneratePublicationTask' property 'generator.pluginsConfiguration.versioning$1.olderVersionsDir' specifies directory '.../docs/older' which doesn't exist.

This was not an error before the v2 Gradle plugin.

Expected behaviour
My project configures the :dokkaGeneratePublicationHtml task with a doFirst lambda that moves the older version directory to the configured path. So the files are present when the task runs, but not before it runs.

It should not be an error to configure this path to a currently non-existent directory. It's undesirable to have the empty directory exist in the file system when the code expects it to only exist temporarily while the API docs are being generated.

To Reproduce
Configure a project with the versioning plugin and set olderVersionsDir to a non-existent path. Then run :dokkaGenerate to see the error.

Dokka configuration
Configuration of dokka used to reproduce the bug

dependencies {
    dokkaPlugin(libs.dokka.versioning)
}

tasks.dokkaGeneratePublicationHtml {
    dokka.pluginsConfiguration.versioning {
        olderVersionsDir = projectDir.resolve("some/non-existent/dir")
        // ...
    }
}

Installation

• Operating system: macOS
• Build tool: Gradle v8.11.1
• Dokka version: 2.0.0

Additional context
Reproducible with my library, Kotbase by removing this line of code: tempOlderDir.mkdir().

[adam-enko]

Thanks for the report, this looks like something that we can fix easily by replacing @InputDirectory with @InputFiles.

gradle/gradle#2016 (comment)

dokka/dokka-runners/dokka-gradle-plugin/src/main/kotlin/engine/plugins/DokkaVersioningPluginParameters.kt

Lines 68 to 71 in 623ee35

	@get:InputDirectory
	@get:PathSensitive(RELATIVE)
	@get:Optional
	abstract val olderVersionsDir: DirectoryProperty