Provide access to Gradle.StartParameter property value in a configuration cache compliant way

[ZakTaccardi]

The following provider does not support the configuration cache.

private fun ProviderFactory.startParameterGradleProperty(
    project: Project,
    propertyName: String
): Provider<String> = provider<String?> {
        project.gradle
            .startParameter
            .projectProperties
            .get(propertyName) as String?
}

Is there a way to access a gradle property defined as a StartParameter (-PsomeProperty=..) that is config cache friendly? Unfortunately, providers.gradleProperty(..) does not work for me here as I need to differentiate between a gradle property passed as a start parameter and one passed in a gradle.properties file.

Use case is https://gist.github.com/ZakTaccardi/a4e1b62b31a7e1069c309a2a169b1058 - which is an attempted workaround to:

• Add official local.properties support #12283
• ProviderFactory#gradleProperty does not work for project-local properties #13302

[Vampire]

Besides that there are a few unnecessary explicit types or casts, what is not configuration cache friendly with your code?
Works perfectly fine here.

[ALikhachev]

@Vampire There's a problem that with configuration cache the value of property from start parameters is cached instead of providing the actual value. For example, we have the use-case when we access project.gradle.startParameter.isOffline. There's no way to mark it as configuration cache input neither to request the actual value on task execution.

[Vampire]

What has that to do with the topic here?
This is about Gradle properties from start parameters. And that works perfectly fine, as any changes in those invalidate the configuration cache.

[ALikhachev]

Yep, you're right. Previously (before Gradle 7.4) the topic was about pretty the same problem.

[ov7a]

Sorry for the late reply.

Thank you for your interest in Gradle!

This feature request is in the backlog of the relevant team, but this area of Gradle is currently not in focus. It might take a while before it gets implemented.