backport bug [ 839151 ] attempt to access sys.argv when it doesn't exist

diff --git a/Lib/warnings.py b/Lib/warnings.py
index 06d7685ece1109876b4d75e2b812fdc0c2df68e1..8d8c36d890109664e8800d0c66e07cee64606d7c 100644 (file)
--- a/Lib/warnings.py
+++ b/Lib/warnings.py
@@ -50,7 +50,11 @@ def warn(message, category=None, stacklevel=1):
             filename = filename[:-1]
     else:
         if module == "__main__":
-            filename = sys.argv[0]
+            try:
+                filename = sys.argv[0]
+            except AttributeError:
+                # embedded interpreters don't have sys.argv, see bug #839151
+                filename = '__main__'
         if not filename:
             filename = module
     registry = globals.setdefault("__warningregistry__", {})