diff --git a/core/drupalci.yml b/core/drupalci.yml
index 66a3b12..bd26f81 100644
--- a/core/drupalci.yml
+++ b/core/drupalci.yml
@@ -4,52 +4,15 @@
 build:
   assessment:
     validate_codebase:
-      phplint:
-      # Re-run composer install to ensure the dependencies resolve for the
-      # containerized PHP version.
-      container_composer:
-        options: ' install --prefer-dist --no-suggest --no-progress --no-interaction'
-        halt-on-fail: true
-      csslint:
-        halt-on-fail: false
-      eslint:
-        # A test must pass eslinting standards check in order to continue processing.
-        halt-on-fail: false
-      phpcs:
-        # phpcs will use core's specified version of Coder.
-        sniff-all-files: false
-        halt-on-fail: false
+      container_command.disableopcache:
+        halt-on-fail: FALSE
+        commands:
+          - sed -i 's/opcache.enable=1/opcache.enable=1\nopcache.optimization_level=0/' /usr/local/etc/php/php.ini
+          - sed -i 's/opcache.enable_cli=1/opcache.enable_cli=1\nopcache.optimization_level=0/' /usr/local/etc/php/php-cli.ini
     testing:
-      # run_tests task is executed several times in order of performance speeds.
-      # halt-on-fail can be set on the run_tests tasks in order to fail fast.
-      # suppress-deprecations is false in order to be alerted to usages of
-      # deprecated code.
-      run_tests.phpunit:
-        types: 'PHPUnit-Unit'
-        testgroups: '--all'
-        suppress-deprecations: false
-        halt-on-fail: false
-      run_tests.kernel:
-        types: 'PHPUnit-Kernel'
-        testgroups: '--all'
-        suppress-deprecations: false
-        halt-on-fail: false
-      run_tests.simpletest:
-         types: 'Simpletest'
-         testgroups: '--all'
-         suppress-deprecations: false
-         halt-on-fail: false
       run_tests.functional:
         types: 'PHPUnit-Functional'
-        testgroups: '--all'
-        suppress-deprecations: false
-        halt-on-fail: false
-      run_tests.javascript:
-        concurrency: 15
-        types: 'PHPUnit-FunctionalJavascript'
-        testgroups: '--all'
+        testgroups: '--class "Drupal\Tests\comment\Functional\CommentCSSTest,Drupal\Tests\migrate_drupal_ui\Functional\d6\MigrateUpgrade6Test,Drupal\Tests\migrate_drupal_ui\Functional\d7\MigrateUpgrade7Test"'
+        repeat: 10
         suppress-deprecations: false
         halt-on-fail: false
-      # Run nightwatch testing.
-      # @see https://www.drupal.org/project/drupal/issues/2869825
-      nightwatchjs:
diff --git a/core/lib/Drupal/Core/Session/SessionManager.php b/core/lib/Drupal/Core/Session/SessionManager.php
index 6071031..252b01d 100644
--- a/core/lib/Drupal/Core/Session/SessionManager.php
+++ b/core/lib/Drupal/Core/Session/SessionManager.php
@@ -218,8 +218,8 @@ public function regenerate($destroy = FALSE, $lifetime = NULL) {
 
     if ($this->isStarted()) {
       $old_session_id = $this->getId();
+      session_regenerate_id($destroy);
     }
-    session_id(Crypt::randomBytesBase64());
 
     $this->getMetadataBag()->clearCsrfTokenSeed();
 
diff --git a/core/lib/Drupal/Core/TempStore/PrivateTempStore.php b/core/lib/Drupal/Core/TempStore/PrivateTempStore.php
index c0003b3..4565088 100644
--- a/core/modules/file/file.module
+++ b/core/modules/file/file.module
@@ -895,13 +895,13 @@ function file_save_upload($form_field_name, $validators = [], $destination = FAL
       case UPLOAD_ERR_FORM_SIZE:
         \Drupal::messenger()->addError(t('The file %file could not be saved because it exceeds %maxsize, the maximum allowed size for uploads.', ['%file' => $file_info->getFilename(), '%maxsize' => format_size(file_upload_max_size())]));
         $files[$i] = FALSE;
-        continue;
+        continue 2;
 
       case UPLOAD_ERR_PARTIAL:
       case UPLOAD_ERR_NO_FILE:
         \Drupal::messenger()->addError(t('The file %file could not be saved because the upload did not complete.', ['%file' => $file_info->getFilename()]));
         $files[$i] = FALSE;
-        continue;
+        continue 2;
 
       case UPLOAD_ERR_OK:
         // Final check that this is a valid upload, if it isn't, use the
@@ -914,7 +914,7 @@ function file_save_upload($form_field_name, $validators = [], $destination = FAL
       default:
         \Drupal::messenger()->addError(t('The file %file could not be saved. An unknown error has occurred.', ['%file' => $file_info->getFilename()]));
         $files[$i] = FALSE;
-        continue;
+        continue 2;
 
     }
     // Begin building file entity.
diff --git a/core/modules/simpletest/simpletest.module b/core/modules/simpletest/simpletest.module
index 0a9c8e5..1d21118 100644
--- a/core/modules/simpletest/simpletest.module
+++ b/core/modules/simpletest/simpletest.module
@@ -855,6 +855,7 @@ function simpletest_phpunit_testcase_to_row($test_id, \SimpleXMLElement $testcas
 
   $attributes = $testcase->attributes();
 
+  $function = $attributes->class . '->' . $attributes->name . '()';
   $record = [
     'test_id' => $test_id,
     'test_class' => (string) $attributes->class,
@@ -862,9 +863,11 @@ function simpletest_phpunit_testcase_to_row($test_id, \SimpleXMLElement $testcas
     'message' => $message,
     // @todo: Check on the proper values for this.
     'message_group' => 'Other',
-    'function' => $attributes->class . '->' . $attributes->name . '()',
+    'function' => $function,
     'line' => $attributes->line ?: 0,
-    'file' => $attributes->file,
+    // There are situations when the file will not be present because a PHPUnit
+    // @requires has caused a test to be skipped.
+    'file' => $attributes->file ?: $function,
   ];
   return $record;
 }
diff --git a/core/tests/Drupal/KernelTests/AssertConfigTrait.php b/core/tests/Drupal/KernelTests/AssertConfigTrait.php
index eb1588f..7acab53 100644
--- a/core/tests/Drupal/KernelTests/AssertConfigTrait.php
+++ b/core/tests/Drupal/KernelTests/AssertConfigTrait.php
@@ -40,7 +40,7 @@ protected function assertConfigDiff(Diff $result, $config_name, array $skipped_c
 
           // Allow to skip entire config files.
           if ($skipped_config[$config_name] === TRUE) {
-            continue;
+            break;
           }
 
           // Allow to skip some specific lines of imported config files.
@@ -71,12 +71,12 @@ protected function assertConfigDiff(Diff $result, $config_name, array $skipped_c
         case 'Drupal\Component\Diff\Engine\DiffOpAdd':
           // The _core property does not exist in the default config.
           if ($op->closing[0] === '_core:') {
-            continue;
+            break;
           }
           foreach ($op->closing as $closing) {
             // The UUIDs don't exist in the default config.
             if (strpos($closing, 'uuid: ') === 0) {
-              continue;
+              break;
             }
             throw new \Exception($config_name . ': ' . var_export($op, TRUE));
           }
diff --git a/core/tests/Drupal/Tests/BrowserTestBase.php b/core/tests/Drupal/Tests/BrowserTestBase.php