this is works fine: ``` val kotlinVersion: String?...

# gradle

[lex]

this is works fine:

val kotlinVersion: String? by extra {
    buildscript.configurations["classpath"]
            .resolvedConfiguration.firstLevelModuleDependencies
            // for gradle 4.4+ change "kotlin-gradle-plugin" to "org.jetbrains.kotlin.jvm.gradle.plugin"
            .find { it.moduleName == "org.jetbrains.kotlin.jvm.gradle.plugin" }?.moduleVersion

}

extra["kotlin.version"] = kotlinVersion
dependencies {
    compile(kotlin("stdlib-jdk8"))
    compile(kotlin("reflect"))
...
}