logging: if logevent_is_boringtwisted fails, print why when we print the exception

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/hippotatlib/__init__.py b/hippotatlib/__init__.py
index 9c2ebfd..588012a 100644 (file)
--- a/hippotatlib/__init__.py
+++ b/hippotatlib/__init__.py
@@ -110,7 +110,8 @@ def logevent_is_boringtwisted(event):
     if dflag is None and DBG.TWISTED in debug_set: return False
     return True
   except Exception:
-    print(traceback.format_exc(), file=org_stderr)
+    print('EXCEPTION (IN BORINGTWISTED CHECK)',
+          traceback.format_exc(), file=org_stderr)
     return False
 
 @implementer(twisted.logger.ILogFilterPredicate)