[3.11] gh-108791: Fix pdb CLI invalid argument handling (GH-108816) (#111063)

* [3.11] gh-108791: Fix `pdb` CLI invalid argument handling (GH-108816)
(cherry picked from commit 162213f2db3835e1115178d38741544f4b4db416)

Co-authored-by: Radislav Chugunov <52372310+chgnrdv@users.noreply.github.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/Lib/pdb.py b/Lib/pdb.py
index 5dfe507..4a4a0b9 100755
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -136,6 +136,9 @@ class _ScriptTarget(str):
         if not os.path.exists(self):
             print('Error:', self.orig, 'does not exist')
             sys.exit(1)
+        if os.path.isdir(self):
+            print('Error:', self.orig, 'is a directory')
+            sys.exit(1)
 
         # Replace pdb's dir with script's dir in front of module search path.
         sys.path[0] = os.path.dirname(self)
@@ -162,6 +165,9 @@ class _ModuleTarget(str):
     def check(self):
         try:
             self._details
+        except ImportError as e:
+            print(f"ImportError: {e}")
+            sys.exit(1)
         except Exception:
             traceback.print_exc()
             sys.exit(1)