complain when there's no last exception
diff --git a/Lib/traceback.py b/Lib/traceback.py
index 3d877ee..b06fcea 100644
--- a/Lib/traceback.py
+++ b/Lib/traceback.py
@@ -241,6 +241,8 @@
def print_last(limit=None, file=None):
"""This is a shorthand for 'print_exception(sys.last_type,
sys.last_value, sys.last_traceback, limit, file)'."""
+ if not hasattr(sys, "last_type"):
+ raise ValueError("no last exception")
if file is None:
file = sys.stderr
print_exception(sys.last_type, sys.last_value, sys.last_traceback,