Catching Throwable instead of Exception

plan.inc.php

@@ -2,6 +2,7 @@
 namespace ATF;
 
 use Exception;
+use Throwable;
 use Amp;
 use taskman;
 
@@ -383,7 +384,7 @@ class Plan
         yield $this->_checkExtStatusAsync($task, $timeout);
         break;
       }
-      catch(Exception $e)
+      catch(Throwable $e)
       {
         $last_error = $e->getMessage();
         continue;