python · jaraco · Jul 28, 2021 · Jul 28, 2021 · Jul 28, 2021 · Jul 28, 2021
diff --git a/Lib/pdb.py b/Lib/pdb.py
@@ -1694,6 +1694,14 @@ def main():
        print('Error:', mainpyfile, 'does not exist')
        sys.exit(1)

+    if run_as_module:
+        import runpy
+        try:
+            runpy._get_module_details(mainpyfile)
+        except Exception:
+            traceback.print_exc()
+            sys.exit(1)
+
    sys.argv[:] = args      # Hide "pdb.py" and pdb options from argument list

    if not run_as_module:

diff --git a/Lib/test/test_pdb.py b/Lib/test/test_pdb.py
@@ -1632,6 +1632,20 @@ def test_module_without_a_main(self):
        self.assertIn("ImportError: No module named t_main.__main__",
                      stdout.splitlines())

+    def test_package_without_a_main(self):
+        pkg_name = 't_pkg'
+        module_name = 't_main'
+        support.rmtree(pkg_name)
+        modpath = pkg_name + '/' + module_name
+        os.makedirs(modpath)
+        with open(modpath + '/__init__.py', 'w') as f:
+            pass
+        self.addCleanup(support.rmtree, pkg_name)
+        stdout, stderr = self._run_pdb(['-m', modpath.replace('/', '.')], "")
+        self.assertIn(
+            "'t_pkg.t_main' is a package and cannot be directly executed",
+            stdout)
+
    def test_blocks_at_first_code_line(self):
        script = """
                #This is a comment, on line 2

diff --git a/Misc/NEWS.d/next/Library/2021-06-29-21-17-17.bpo-44461.acqRnV.rst b/Misc/NEWS.d/next/Library/2021-06-29-21-17-17.bpo-44461.acqRnV.rst
@@ -0,0 +1 @@
+Fix bug with :mod:`pdb`'s handling of import error due to a package which does not have a ``__main__`` module
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Fix bug with :mod:`pdb`'s handling of import error due to a package which does not have a ``__main__`` module