Add function to get toolchain JDK home location

buildSrc/src/main/kotlin/JvmToolchain.kt

@@ -1,4 +1,5 @@
 @file:JvmName("JvmToolchain")
+
 import org.gradle.api.Project
 import org.gradle.api.plugins.JavaPluginExtension
 import org.gradle.api.provider.Provider
@@ -195,6 +196,12 @@ fun Project.getToolchainLauncherFor(
     }
 }
 
+fun Project.getToolchainJdkHomeFor(jdkVersion: JdkMajorVersion): Provider<String> {
+    return getToolchainLauncherFor(jdkVersion).map {
+        it.metadata.installationPath.asFile.absolutePath
+    }
+}
+
 
 fun Project.getJdkVersionWithOverride(jdkVersion: JdkMajorVersion): JdkMajorVersion {
     return if (project.shouldOverrideObsoleteJdk(jdkVersion)) {

buildSrc/src/main/kotlin/tasks.kt

@@ -258,8 +258,8 @@ fun Project.projectTest(
         }
 
         defineJDKEnvVariables.forEach { version ->
-            val javaLauncher = project.getToolchainLauncherFor(version).orNull ?: error("Can't find toolchain for $version")
-            environment(version.envName, javaLauncher.metadata.installationPath.asFile.absolutePath)
+            val jdkHome = project.getToolchainJdkHomeFor(version).orNull ?: error("Can't find toolchain for $version")
+            environment(version.envName, jdkHome)
         }
     }.apply { configure(body) }
 }