Client: Fixed memory leak in Error object

warden3/warden_client/warden_client.py

@@ -120,6 +120,14 @@ class Error(Exception):
                 kwargs["send_events_limit"] = int(kwargs["send_events_limit"])
             except Exception:
                 del kwargs["send_events_limit"]
+        if "exc" in kwargs:
+            # Traceback objects cause reference loops, so memory may be not
+            # correctly free'd. We only need traceback to log it in str_debug(),
+            # so let's get the string representation now and forget the 
+            # traceback object, thus preventing the loop.
+            exctype, excvalue, tb = kwargs["exc"]
+            tb = format_tb(tb)
+            kwargs["exc"] = exctype, excvalue, tb
         self.errors.append(kwargs)
 
 
@@ -211,10 +219,10 @@ class Error(Exception):
         out.append(self.str_preamble(e))
         if not "exc" in e or not e["exc"]:
             return ""
-        exc_tb = e["exc"][2]
+        exc_tb = e["exc"][2] # exc_tb is string repr. of traceback object
         if exc_tb:
             out.append("Traceback:\n")
-            out.extend(format_tb(exc_tb))
+            out.extend(exc_tb)
         return "".join(out)