This message was deleted.

it really depends on how you want to use this environment variable. If you’re launching a JVM process, then you can set an environment variable for that process based on a property from

gradle.properties

. Or if you just want some variable that might come from

gradle.properties

on one machine, but is set via an environment variable on another machine, then you can use a project property Can you explain more about what you want to achieve?

Sure. I'm using JGit programmatically directly as part of my

build.gradle.kts

file. When probing for the Git system config, JGit eventually calls out to the system's

git

CLI, which is incompatible with Gradle's new configuration caching. JGit's behavior can be suppressed by setting the

GIT_CONFIG_NOSYSTEM

environment variable, and that's what I'd like to do.

funnily enough I’m also trying to work around that JGit issue at the moment! It would be nice to have a build service for Git operations that was config-cache compatible

Looks like an alternative could be use a custom FS that makes

getGitSystemConfig

return null.

Can you wrap jgit call to ValueSource and can that make it compatible with cc?

@Anze Sodja I tried with a top-level class in my

build.gradle.kts

file but I'm getting

* What went wrong:
Could not create an instance of type Build_gradle$GitVersionValueSource.
> Class Build_gradle.GitVersionValueSource is a non-static inner class.

You need to pass what you want to use in ValueSource via parameters, e.g.:

// Kotlin
abstract class MyValueSource : ValueSource<String, MyValueSource.MyValueSourceParams> {

    private val logger = Logging.getLogger(MyValueSource::class.java)

    interface MyValueSourceParams : ValueSourceParameters {
        val rootDir: DirectoryProperty
    }

    override fun obtain(): String {
        logger.lifecycle("In value source: " + parameters.rootDir.get().asFile.path)
        return parameters.rootDir.get().asFile.path
    }
}

val provider = providers.of(MyValueSource::class) {
    parameters {
        rootDir.set(project.rootDir)
    }
    // or just parameters.rootDir.set(project.rootDir)
}

println(provider.get())

Thanks. As I have several JGit calls that each would require a separate

ValueSource

, I decided to go with the solution of a custom

SystemReader

as mentioned at https://stackoverflow.com/a/59110721/1127485 instead.

I'm maybe a bit late to the party, but this works perfectly fine and only needs one

ValueSource

to bootstrap JGit if a new Daemon was started with not missing the system config which the SO answer causes:

import org.eclipse.jgit.storage.file.FileRepositoryBuilder

plugins {
    id("org.ajoberstar.grgit.service") version "5.2.0"
}

abstract class JGitBootstrapper : ValueSource<String, JGitBootstrapper.Parameters> {
    override fun obtain(): String {
        FileRepositoryBuilder()
            .setWorkTree(parameters.projectDirectory.get().asFile)
            .build()
        return ""
    }

    interface Parameters : ValueSourceParameters {
        val projectDirectory: DirectoryProperty
    }
}

providers.of(JGitBootstrapper::class) {
    parameters {
        projectDirectory.set(layout.projectDirectory)
    }
}.get()

println(grgitService.service.get().grgit.head().id)

This way the external proess execution at configuration time is properly wrapped in a

ValueSource

, and it is only done once in the daemon lifetime as it is done as part of a static initialization. The actual Git operations done at configuration time then cause the accessed files and environment variables to be configuration cache inputs as usual. So if you execute this snippet two times, the second time nothing is printed. If you then create a new commit and rerun without other changes, it is rerun and prints again.