drupal simpletest stuffs

make simpletest fail if one of the child processes does

diff --git run-tests.sh run-tests.sh
index bcc5095..e0022fd 100755
--- run-tests.sh
+++ run-tests.sh
@@ -387,7 +387,11 @@ function simpletest_script_command($concurrency, $test_id, $tests) {
     $command .= ' --color';
   }
   $command .= " --php " . escapeshellarg($php) . " --concurrency $concurrency --test-id $test_id --execute-batch $tests";
-  passthru($command);
+  passthru($command, $output);
+  if ($output == 255) {
+    echo "Caught a fatal error, sorry I have no more information for you than that.";
+    exit(1);
+  } 
 }
 
 /**