Arun Sahijpal
--- a/core/lib/Drupal/Core/Template/Attribute.php
+++ b/core/lib/Drupal/Core/Template/Attribute.php
   * {@inheritdoc}
   */
  public function offsetSet($name, $value): void {
+    // Check if the attribute name contains a space.
+    if (strpos($name, ' ') !== FALSE) {
+      \Drupal::logger('system')->warning('Invalid attribute name "@name" detected. Attribute names cannot contain spaces.', ['@name' => $name]);
--- a/core/lib/Drupal/Core/Template/Attribute.php
+++ b/core/lib/Drupal/Core/Template/Attribute.php
+  protected $logger;
+
  /**
   * Constructs a \Drupal\Core\Template\Attribute object.
   *
   * @param array $attributes
   *   An associative array of key-value pairs to be converted to attributes.
+   * @param \Psr\Log\LoggerInterface $logger
+   *   The logger.
   */
-  public function __construct($attributes = []) {
+  public function __construct($attributes = [], ?LoggerInterface $logger = NULL) {
    foreach ($attributes as $name => $value) {
      $this->offsetSet($name, $value);
    }
+    $this->logger = $logger;