Issue #3311472 Set minimum stability for form

Closes #3311472

package_manager/src/StageBase.php

@@ -578,6 +578,8 @@ abstract class StageBase implements LoggerAwareInterface {
     }
 
     if (isset($error)) {
+      // Ensure the error is logged for post-mortem diagnostics.
+      Error::logException($this->logger, $error);
       if ($on_error) {
         $on_error();
       }