diff --git a/core/scripts/run-tests.sh b/core/scripts/run-tests.sh
index 1b8d5b2..2b75d70 100755
--- a/core/scripts/run-tests.sh
+++ b/core/scripts/run-tests.sh
@@ -38,9 +38,15 @@
 
 simpletest_script_init();
 
-$request = Request::createFromGlobals();
-$kernel = TestRunnerKernel::createFromRequest($request, $autoloader);
-$kernel->prepareLegacyRequest($request);
+try {
+  $request = Request::createFromGlobals();
+  $kernel = TestRunnerKernel::createFromRequest($request, $autoloader);
+  $kernel->prepareLegacyRequest($request);
+}
+catch (Exception $e) {
+  echo (string) $e;
+  exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+}
 
 if ($args['execute-test']) {
   simpletest_script_setup_database();
@@ -53,7 +59,13 @@
   // Display all available tests.
   echo "\nAvailable test groups & classes\n";
   echo   "-------------------------------\n\n";
-  $groups = simpletest_test_get_all($args['module']);
+  try {
+    $groups = simpletest_test_get_all($args['module']);
+  }
+  catch (Exception $e) {
+    echo (string) $e;
+    exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+  }
   foreach ($groups as $group => $tests) {
     echo $group . "\n";
     foreach ($tests as $class => $info) {
@@ -67,7 +79,13 @@
 
 if ($args['clean']) {
   // Clean up left-over tables and directories.
-  simpletest_clean_environment();
+  try {
+    simpletest_clean_environment();
+  }
+  catch (Exception $e) {
+    echo (string) $e;
+    exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+  }
   echo "\nEnvironment cleaned.\n";
 
   // Get the status messages and print them.
@@ -109,7 +127,13 @@
 
 // Clean up all test results.
 if (!$args['keep-results']) {
-  simpletest_clean_results_table();
+  try {
+    simpletest_clean_results_table();
+  }
+  catch (Exception $e) {
+    echo (string) $e;
+    exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+  }
 }
 
 // Test complete, exit.
@@ -499,16 +523,28 @@ function simpletest_script_setup_database($new = FALSE) {
   if ($new && $sqlite) {
     require_once DRUPAL_ROOT . '/' . drupal_get_path('module', 'simpletest') . '/simpletest.install';
     foreach (simpletest_schema() as $name => $table_spec) {
-      if ($schema->tableExists($name)) {
-        $schema->dropTable($name);
+      try {
+        if ($schema->tableExists($name)) {
+          $schema->dropTable($name);
+        }
+        $schema->createTable($name, $table_spec);
+      }
+      catch (Exception $e) {
+        echo (string) $e;
+        exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
       }
-      $schema->createTable($name, $table_spec);
     }
   }
   // Verify that the Simpletest database schema exists by checking one table.
-  if (!$schema->tableExists('simpletest')) {
-    simpletest_script_print_error('Missing Simpletest database schema. Either install Simpletest module or use the --sqlite parameter.');
-    exit(SIMPLETEST_SCRIPT_EXIT_FAILURE);
+  try {
+    if (!$schema->tableExists('simpletest')) {
+      simpletest_script_print_error('Missing Simpletest database schema. Either install Simpletest module or use the --sqlite parameter.');
+      exit(SIMPLETEST_SCRIPT_EXIT_FAILURE);
+    }
+  }
+  catch (Exception $e) {
+    echo (string) $e;
+    exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
   }
 }
 
@@ -528,8 +564,16 @@ function simpletest_script_execute_batch($test_classes) {
         break;
       }
 
-      $test_id = Database::getConnection('default', 'test-runner')
-        ->insert('simpletest_test_id')->useDefaults(array('test_id'))->execute();
+      try {
+        $test_id = Database::getConnection('default', 'test-runner')
+          ->insert('simpletest_test_id')
+          ->useDefaults(array('test_id'))
+          ->execute();
+      }
+      catch (Exception $e) {
+        echo (string) $e;
+        exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+      }
       $test_ids[] = $test_id;
 
       $test_class = array_shift($test_classes);
@@ -731,7 +775,13 @@ function simpletest_script_cleanup($test_id, $test_class, $exitcode) {
     return;
   }
   // Retrieve the last database prefix used for testing.
-  list($db_prefix, ) = simpletest_last_test_get($test_id);
+  try {
+    list($db_prefix,) = simpletest_last_test_get($test_id);
+  }
+  catch (Exception $e) {
+    echo (string) $e;
+    exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+  }
 
   // If no database prefix was found, then the test was not set up correctly.
   if (empty($db_prefix)) {
@@ -746,7 +796,13 @@ function simpletest_script_cleanup($test_id, $test_class, $exitcode) {
   $messages[] = "- Found database prefix '$db_prefix' for test ID $test_id.";
 
   // Read the log file in case any fatal errors caused the test to crash.
-  simpletest_log_read($test_id, $db_prefix, $test_class);
+  try {
+    simpletest_log_read($test_id, $db_prefix, $test_class);
+  }
+  catch (Exception $e) {
+    echo (string) $e;
+    exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+  }
 
   // Check whether a test site directory was setup already.
   // @see \Drupal\simpletest\TestBase::prepareEnvironment()
@@ -768,12 +824,19 @@ function simpletest_script_cleanup($test_id, $test_class, $exitcode) {
   }
 
   // Clear out all database tables from the test.
-  $schema = Database::getConnection('default', 'default')->schema();
-  $count = 0;
-  foreach ($schema->findTables($db_prefix . '%') as $table) {
-    $schema->dropTable($table);
-    $count++;
+  try {
+    $schema = Database::getConnection('default', 'default')->schema();
+    $count = 0;
+    foreach ($schema->findTables($db_prefix . '%') as $table) {
+      $schema->dropTable($table);
+      $count++;
+    }
   }
+  catch (Exception $e) {
+    echo (string) $e;
+    exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+  }
+
   if ($count) {
     $messages[] = "- Removed $count leftover tables.";
   }
@@ -797,7 +860,13 @@ function simpletest_script_get_test_list() {
 
   $test_list = array();
   if ($args['all'] || $args['module']) {
-    $groups = simpletest_test_get_all($args['module']);
+    try {
+      $groups = simpletest_test_get_all($args['module']);
+    }
+    catch (Exception $e) {
+      echo (string) $e;
+      exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+    }
     $all_tests = array();
     foreach ($groups as $group => $tests) {
       $all_tests = array_merge($all_tests, array_keys($tests));
@@ -813,7 +882,13 @@ function simpletest_script_get_test_list() {
           $test_list[] = $test_class;
         }
         else {
-          $groups = simpletest_test_get_all();
+          try {
+            $groups = simpletest_test_get_all();
+          }
+          catch (Exception $e) {
+            echo (string) $e;
+            exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+          }
           $all_classes = array();
           foreach ($groups as $group) {
             $all_classes = array_merge($all_classes, array_keys($group));
@@ -854,7 +929,13 @@ function simpletest_script_get_test_list() {
       }
     }
     else {
-      $groups = simpletest_test_get_all();
+      try {
+        $groups = simpletest_test_get_all();
+      }
+      catch (Exception $e) {
+        echo (string) $e;
+        exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+      }
       foreach ($args['test_names'] as $group_name) {
         if (isset($groups[$group_name])) {
           $test_list = array_merge($test_list, array_keys($groups[$group_name]));
@@ -944,7 +1025,13 @@ function simpletest_script_reporter_display_summary($class, $results) {
 function simpletest_script_reporter_write_xml_results() {
   global $args, $test_ids, $results_map;
 
-  $results = simpletest_script_load_messages_by_test_id($test_ids);
+  try {
+    $results = simpletest_script_load_messages_by_test_id($test_ids);
+  }
+  catch (Exception $e) {
+    echo (string) $e;
+    exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+  }
 
   $test_class = '';
   $xml_files = array();
@@ -1034,7 +1121,13 @@ function simpletest_script_reporter_display_results() {
     echo "Detailed test results\n";
     echo "---------------------\n";
 
-    $results = simpletest_script_load_messages_by_test_id($test_ids);
+    try {
+      $results = simpletest_script_load_messages_by_test_id($test_ids);
+    }
+    catch (Exception $e) {
+      echo (string) $e;
+      exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+    }
     $test_class = '';
     foreach ($results as $result) {
       if (isset($results_map[$result->status])) {
@@ -1178,10 +1271,16 @@ function simpletest_script_load_messages_by_test_id($test_ids) {
   }
 
   foreach ($test_id_chunks as $test_id_chunk) {
-    $result_chunk = Database::getConnection('default', 'test-runner')
-      ->query("SELECT * FROM {simpletest} WHERE test_id IN ( :test_ids[] ) ORDER BY test_class, message_id", array(
-        ':test_ids[]' => $test_id_chunk,
-      ))->fetchAll();
+    try {
+      $result_chunk = Database::getConnection('default', 'test-runner')
+        ->query("SELECT * FROM {simpletest} WHERE test_id IN ( :test_ids[] ) ORDER BY test_class, message_id", array(
+          ':test_ids[]' => $test_id_chunk,
+        ))->fetchAll();
+    }
+    catch (Exception $e) {
+      echo (string) $e;
+      exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+    }
     if ($result_chunk) {
       $results = array_merge($results, $result_chunk);
     }
@@ -1196,14 +1295,20 @@ function simpletest_script_load_messages_by_test_id($test_ids) {
 function simpletest_script_open_browser() {
   global $test_ids;
 
-  $connection = Database::getConnection('default', 'test-runner');
-  $results = $connection->select('simpletest')
-    ->fields('simpletest')
-    ->condition('test_id', $test_ids, 'IN')
-    ->orderBy('test_class')
-    ->orderBy('message_id')
-    ->execute()
-    ->fetchAll();
+  try {
+    $connection = Database::getConnection('default', 'test-runner');
+    $results = $connection->select('simpletest')
+      ->fields('simpletest')
+      ->condition('test_id', $test_ids, 'IN')
+      ->orderBy('test_class')
+      ->orderBy('message_id')
+      ->execute()
+      ->fetchAll();
+  }
+  catch (Exception $e) {
+    echo (string) $e;
+    exit(SIMPLETEST_SCRIPT_EXIT_EXCEPTION);
+  }
 
   // Get the results form.
   $form = array();