Main class name in MANIFEST file

I’m trying to build a fat jar, but I don’t know what I should provide as ‘Main-Class’. The program consists of a Kotlin file, name “App.kt” with a single main method like this:

fun main(args: Array<String>) {
  println("hello, world!")
}

The Gradle build file looks like this:

group 'com.example'
version '1.0'

buildscript {
    ext.kotlin_version = '1.0.3'

    repositories {
        mavenCentral()
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

apply plugin: 'kotlin'

repositories {
    mavenCentral()
}

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
}

task bigJar(type: Jar) {
    manifest {
        attributes 'Implementation-Title': 'Table of Contents Fix for Hugo',
                'Implementation-Version': version,
                'Main-Class': 'com.example.project.App'
    }
    baseName = project.name
    from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
    with jar
}

But if I try to execute the jar file, I get the error that the Main class “com.example.project.App” could not be found.

What is the correct main class name?

As documented here the main class name will be AppKt.

Thank you.