Drupal 10.3 Element children from User Error to throw an exception breaks any non render array (but still array) output

[DiegoPino]

What?

Drupal! Devs (to make tests pass and use the new PHP UNIT 10 stuff) made a large breaking change. Any Array output via {{ data.i_am_an_array }} will no longer show a user error on screen but will basically kill the page.

See https://git.drupalcode.org/project/drupal/-/commit/3d645c1b3c

The reason is someone decided to override in Drupal Core the normal Twig Escape Extension (the default)

Which in turn calls this code with a silly message (no, not handled!!!)

  // This is a normal render array, which is safe by definition, with
  // special simple cases already handled.
  
  // Early return if this element was pre-rendered (no need to re-render).
    if (isset($arg['#printed']) && $arg['#printed'] == TRUE && isset($arg['#markup']) && strlen($arg['#markup']) > 0) {
      return $arg['#markup'];
    }
    $arg['#printed'] = FALSE;
    return $this->renderer->render($arg);

And $this->renderer->render($arg);

and renderer::render will call
Renderer.php:462, Drupal\Core\Render\Renderer->doRender()
Element.php:97, Drupal\Core\Render\Element::children()

Throwing an exception nobody is catching and not only failing to render a single piece, but the whole page

I need to think how to override for our use case this. There is a LOT of code happening and too many layers.