scala assertions aren't disabled by jvm commandline options

gistfile1.txt

package example;

public class JavaExample {
  public static void main(String[] args) {
    System.out.println("before assert");
    assert 1 == 0;
    System.out.println("after asssert");
  }
}

package example

object ScalaExample {
  def main(args: Array[String]): Unit = {
    println("before assert")
    assert(1 == 0, "Boom!")
    println("after assert")
  }
}


bash-3.2$ java -ea -cp /private/var/tmp/test-assertions/target/scala-2.12/test-assertions-assembly-0.1-SNAPSHOT.jar example.JavaExample
before assert
Exception in thread "main" java.lang.AssertionError
        at example.JavaExample.main(JavaExample.java:6)
bash-3.2$ java -da -cp /private/var/tmp/test-assertions/target/scala-2.12/test-assertions-assembly-0.1-SNAPSHOT.jar example.JavaExample
before assert
after asssert
bash-3.2$ java -ea -cp /private/var/tmp/test-assertions/target/scala-2.12/test-assertions-assembly-0.1-SNAPSHOT.jar example.ScalaExample
before assert
Exception in thread "main" java.lang.AssertionError: assertion failed: Boom!
        at scala.Predef$.assert(Predef.scala:219)
        at example.ScalaExample$.main(Example.scala:6)
        at example.ScalaExample.main(Example.scala)
bash-3.2$ java -da -cp /private/var/tmp/test-assertions/target/scala-2.12/test-assertions-assembly-0.1-SNAPSHOT.jar example.ScalaExample
before assert
Exception in thread "main" java.lang.AssertionError: assertion failed: Boom!
        at scala.Predef$.assert(Predef.scala:219)
        at example.ScalaExample$.main(Example.scala:6)
        at example.ScalaExample.main(Example.scala)