Question

I’ve created an SBT 0.11 project of an only one source code file (yet):

object HelloWorld extends App {
  println("Hello, world!")
}

When try to run the application with SBT, I get “java.lang.RuntimeException: No main class detected”.

How do I define the main class?

I have used “full configuration” with the folowing Build.scala:

import sbt._

object MyBuild extends Build {
  lazy val HelloWorld = Project("HelloWorld ", file("src"))
}

And the following build.sbt:

name := "HelloWorld"

version := "1.0"

scalaVersion := "2.9.1"

Answer 1

Try replacing:

lazy val HelloWorld = Project("HelloWorld ", file("src"))

with:

lazy val HelloWorld = Project("HelloWorld ", file("."))