$ copy-file changes/RunSuccess.scala src/main/scala/Run.scala
> run

# an exception in the main thread should be a nonzero exit code
$ copy-file changes/RunFailureMain.scala src/main/scala/Run.scala
-> run

# an exception in a non-main thread should still be exit code 0
$ copy-file changes/ThreadRunError.scala src/main/scala/Run.scala
> run

# explicitly calling System.exit(0) should succeed
$ copy-file changes/RunExplicitSuccess.scala src/main/scala/Run.scala
> run

# explicitly calling System.exit(1) should fail the 'run' task
$ copy-file changes/RunExplicitFailure.scala src/main/scala/Run.scala
-> run