update.php reports failure without details

+++ b/core/modules/system/src/Controller/DbUpdateController.php
@@ -339,6 +339,9 @@ protected function selection(Request $request) {
+      if (isset($update['warning'])) {
+        $this->messenger()->addWarning($this->t($update['warning']));
+      }

$update['warning'] can't be run through t() because it's a variable, can just skip the $this->t().

I think #4 is is suggesting to just replace isset() with !empty() and that seems worth doing for robustness.

Updated #18 as per #23

The last submitted patch, 24: 2189429-24.patch, failed testing. View results →

Now that the string is not being translated it needs to be escaped correctly.