bpo-44461: Check early that a pdb target is valid for execution. (#27227)

* bpo-44461: Fix bug with pdb's handling of import error due to a package which does not have a __main__ module

* 📜🤖 Added by blurb_it.

* remove "else"

Co-authored-by: Jason R. Coombs <jaraco@jaraco.com>

* If running as a module, first check that it can run as a module. Alternate fix for bpo-44461.

Co-authored-by: Irit Katriel <iritkatriel@yahoo.com>
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/Lib/pdb.py b/Lib/pdb.py
index e769ad7..8aa899f 100755
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -169,7 +169,11 @@ class ScriptTarget(str):
 
 class ModuleTarget(str):
     def check(self):
-        pass
+        try:
+            self._details
+        except Exception:
+            traceback.print_exc()
+            sys.exit(1)
 
     @functools.cached_property
     def _details(self):