NoSuchMethodException launching Scala App

This is a pretty standard thing to do in Java:

public class App {
	public static void main(String[] args) {
		App app = new App();
		app.start();
	}

	public void start() {
		// do something
	}
}

So you reckon you’d be able to do this in Scala:

object App {
	def main(args: Array[String]) = {
		val app = new App()
		app.start()
	}
}

class App() {
	def start() = {
		// do something
	}
}

You go to run it and:
Exception in thread "main" java.lang.NoSuchMethodException: id.jakubkorab.App.main([Ljava.lang.String;)
at java.lang.Class.getMethod(Class.java:1605)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:107)

Turns out the Scala compiler doesn’t treat application launching in the same way that it treats other classes with companion objects. If you rename the object App to another name, it works.

object AppLauncher {
	def main(args: Array[String]) = {
		val app = new App()
		app.start()
	}
}

Go figure.