xdebug break for core element.php invalid attribute

invalid_attribute_xdebug_break.patch

diff --git a/core/lib/Drupal/Core/Render/Element.php b/core/lib/Drupal/Core/Render/Element.php
index e394a39..32755f2 100644
--- a/core/lib/Drupal/Core/Render/Element.php
+++ b/core/lib/Drupal/Core/Render/Element.php
@@ -94,6 +94,7 @@ public static function children(array &$elements, $sort = FALSE) {
         // Only trigger an error if the value is not null.
         // @see https://www.drupal.org/node/1283892
         elseif (isset($value)) {
+          xdebug_break();
           trigger_error(SafeMarkup::format('"@key" is an invalid render array key', ['@key' => $key]), E_USER_ERROR);
         }
       }