message: Flush out at the end
diff: @@ -229,6 +229,7 @@ pub fn execute<T: std::io::Write>(
  next_block_idx = Some(curr_block.exit[exit_idx]);
  }
  Ret { .. } => {
  + out.flush().map_err(|e| InterpError::IoError(Box::new(e)))?;
  // NOTE: This only works so long as `main` is the only function
  return Ok(());
  }
  @@ -263,6 +264,7 @@ pub fn execute<T: std::io::Write>(
  if let Some(idx) = next_block_idx {
  curr_block_idx = idx;
  } else {
  + out.flush().map_err(|e| InterpError::IoError(Box::new(e)))?;
  return Ok(());
  }
  }
  