diff --git a/synapse/util/logformatter.py b/synapse/util/logformatter.py
index 60504162e9..cdbc4bffd7 100644
--- a/synapse/util/logformatter.py
+++ b/synapse/util/logformatter.py
@@ -33,9 +33,17 @@ class LogFormatter(logging.Formatter):
def formatException(self, ei):
sio = StringIO.StringIO()
- sio.write("Capture point (most recent call last):\n")
- traceback.print_stack(ei[2].tb_frame.f_back, None, sio)
- traceback.print_exception(ei[0], ei[1], ei[2], None, sio)
+ (typ, val, tb) = ei
+
+ # log the stack above the exception capture point if possible, but
+ # check that we actually have an f_back attribute to work around
+ # https://twistedmatrix.com/trac/ticket/9305
+
+ if tb and hasattr(tb.tb_frame, 'f_back'):
+ sio.write("Capture point (most recent call last):\n")
+ traceback.print_stack(tb.tb_frame.f_back, None, sio)
+
+ traceback.print_exception(typ, val, tb, None, sio)
s = sio.getvalue()
sio.close()
if s[-1:] == "\n":
|
