Drupal 8 - How To Make A "line 42 of core/modules/system/src/Element/StatusReportPage.php" Error Go Away

CentOS 7 / Drupal 8

How To Make A "line 42 of core/modules/system/src/Element/StatusReportPage.php" Error Go Away

tl;dr:  Skip down to Fixing Ubercart

After installing Ubercart 7 on our eCommerce website, I started to see these errors in the Drupal 8 Administration GUI:

Hmmm.  Let's have a look at the offending line of code, shall we?

    // Loop through requirements and pull out items.

    foreach ($element['#requirements'] as $key => $requirement) {

      switch ($key) {

        case 'cron':

          foreach ($requirement['description'] as &$description_elements) {

            foreach ($description_elements as &$description_element) {

              if (isset($description_element['#url']) && $description_element['#url']->getRouteName() == 'system.run_cron') {

                $description_element['#attributes']['class'][] = 'button';

                $description_element['#attributes']['class'][] = 'button--small';

                $description_element['#attributes']['class'][] = 'button--primary';

                $description_element['#attributes']['class'][] = 'system-status-general-info__run-cron';

              }

            }

          }

          // Intentional fall-through.

Well, Line 42 of StatusReportPage.php seems to want to know something about the $description_element members that result from stepping through the $requirements array, which seems to hold a description of something.

Fixing Ubercart:

Ultimately, this boiled down to a bug in Ubercart 7, and it's an easy fix once ferreted out.

Just add a single line of code to  uc_store.install in the uc_store subdirectory of ubercart:

function uc_store_requirements($phase) {

  $requirements = [];

  if ($phase == 'runtime') {

    $severities = [

      'warning' => REQUIREMENT_WARNING,

      'error' => REQUIREMENT_ERROR,

    ];

    $results = \Drupal::moduleHandler()->invokeAll('uc_store_status');

    foreach ($results as $status) {

      $requirements[] = [

        'severity' => isset($severities[$status['status']]) ? $severities[$status['status']] : NULL,

        'title' => $status['title'],

        'value' => $status['desc'],

        'description' => [],

      ];

    }

  }

  return $requirements;

}

Once that line of code was added, the error went away:

Great Success!

(my thanks to bjaxelson for a great clue as to the ultimate source of this error!)

REFERENCES:

https://www.drupal.org/project/drupal/issues/2876308