gh-148615: Handle -- end-of-options separator in pdb argument parsing

Lib/pdb.py

@@ -3634,6 +3634,10 @@ def parse_args():
         opt_module = parser.parse_args(args[:2])
         opts.module = opt_module.module
         args = args[2:]
+    elif args[0] == '--':
+        args.pop(0)
+        if not args:
+            parser.error("missing script or module to run")
     elif args[0].startswith('-'):
         # Invalid argument before the script name.
         invalid_args = list(itertools.takewhile(lambda a: a.startswith('-'), args))

Lib/test/test_pdb.py

@@ -4173,6 +4173,20 @@ def test_run_script_with_args(self):
         stdout, stderr = self.run_pdb_script(script, commands, script_args=["--bar", "foo"])
         self.assertIn("['--bar', 'foo']", stdout)
 
+    def test_run_script_with_double_dash(self):
+        script = "import sys; print(sys.argv)"
+        commands = "continue\nquit"
+        filename = 'main.py'
+        with open(filename, 'w') as f:
+            f.write(script)
+        self.addCleanup(os_helper.unlink, filename)
+        stdout, _ = self._run_pdb(["--", filename, "-c", "example"], commands)
+        self.assertIn(f"['{filename}', '-c', 'example']", stdout)
+        stdout, _ = self._run_pdb(["-c", "continue", "--", filename, "-c", "example"], "quit")
+        self.assertIn(f"['{filename}', '-c', 'example']", stdout)
+        stdout, stderr = self._run_pdb(["--"], "", expected_returncode=2)
+        self.assertIn("pdb: error: missing script or module to run", stderr)
+
     def test_breakpoint(self):
         script = """
             if __name__ == '__main__':
@@ -5196,6 +5210,35 @@ def test_interact_completion(self):
         self.assertIn(b'84', output)
 
 
+class PdbCommandLineTestCase(unittest.TestCase):
+    def test_end_of_options_separator(self):
+        # gh-148615: Test parsing when '--' separator is used
+        from pdb import parse_args
+        with patch('sys.argv', ['pdb.py', '--', 'my_script.py', '-foo']):
+            opts, args = parse_args()
+            self.assertEqual(args, ['my_script.py', '-foo'])
+        with patch('sys.argv', ['pdb.py', '-c', 'continue', '--', 'my_script.py', '-c', 'foo']):
+            opts, args = parse_args()
+            self.assertEqual(opts.commands, ['continue'])
+            self.assertEqual(args, ['my_script.py', '-c', 'foo'])
+        with patch('sys.argv', ['pdb.py', '--']):
+            with support.captured_stderr() as stderr:
+                with self.assertRaises(SystemExit):
+                    parse_args()
+            self.assertIn("missing script or module to run", stderr.getvalue())
+        with patch('sys.argv', ['pdb.py', '-x', '--', 'my_script.py']):
+            with support.captured_stderr() as stderr:
+                with self.assertRaises(SystemExit):
+                    parse_args()
+            self.assertIn("unrecognized arguments: -x", stderr.getvalue())
+        with patch('sys.argv', ['pdb.py', 'foo', '--', 'my_script.py']):
+            opts, args = parse_args()
+            self.assertEqual(args, ['foo', '--', 'my_script.py'])
+        with patch('sys.argv', ['pdb.py', '-m', 'my_module', '--', 'foo']):
+            opts, args = parse_args()
+            self.assertEqual(opts.module, 'my_module')
+            self.assertEqual(args, ['--', 'foo'])
+
 def load_tests(loader, tests, pattern):
     from test import test_pdb
 

Misc/NEWS.d/next/Library/2026-04-15-16-08-12.gh-issue-148615.Uvx50R.rst

@@ -0,0 +1,3 @@
+Fix :mod:`pdb` to accept standard ``--`` end of options separator,
+which was inadvertently rejected since the switch from :mod:`getopt` to
+:mod:`argparse` in Python 3.13. Reported by haampie. Patched by Shrey Naithani.