gh-102778: IDLE - make sys.last_exc available in Shell after traceback (#103314)

---------
Co-authored-by: Terry Jan Reedy <[email protected]>

Author: iritkatriel

Lib/idlelib/run.py

@@ -239,6 +239,7 @@ def print_exception():
     efile = sys.stderr
     typ, val, tb = excinfo = sys.exc_info()
     sys.last_type, sys.last_value, sys.last_traceback = excinfo
+    sys.last_exc = val
     seen = set()
 
     def print_exc(typ, exc, tb):

Misc/NEWS.d/next/Library/2023-04-06-16-55-51.gh-issue-102778.BWeAmE.rst

@@ -0,0 +1 @@
+Support ``sys.last_exc`` in :mod:`idlelib`.