[3.2.x] Fixed #32783 -- Fixed crash of autoreloader when __main__ module doesn't have __spec__ attribute.

Regression in ec6d2531c59466924b645f314ac33f54470d7ac3.

Thanks JonathanNickelson for the report.
Backport of 12b19a1d76e1a6f80923c8358290d605dacd65d4 from main

django/utils/autoreload.py

@@ -222,7 +222,8 @@ def get_child_arguments():
     args = [sys.executable] + ['-W%s' % o for o in sys.warnoptions]
     # __spec__ is set when the server was started with the `-m` option,
     # see https://docs.python.org/3/reference/import.html#main-spec
-    if __main__.__spec__ is not None and __main__.__spec__.parent:
+    # __spec__ may not exist, e.g. when running in a Conda env.
+    if getattr(__main__, '__spec__', None) is not None and __main__.__spec__.parent:
         args += ['-m', __main__.__spec__.parent]
         args += sys.argv[1:]
     elif not py_script.exists():

docs/releases/3.2.4.txt

@@ -25,3 +25,6 @@ Bugfixes
   
 * Fixed a bug in Django 3.2 that would trigger the auto-reloader for template
   changes when directory paths were specified with strings (:ticket:`32744`).
+
+* Fixed a regression in Django 3.2 that caused a crash of auto-reloader with
+  ``AttributeError``, e.g. inside a ``Conda`` environment (:ticket:`32783`).

tests/utils_tests/test_autoreload.py

@@ -213,6 +213,17 @@ class TestChildArguments(SimpleTestCase):
         with self.assertRaisesMessage(RuntimeError, msg):
             autoreload.get_child_arguments()
 
+    @mock.patch('sys.argv', [__file__, 'runserver'])
+    @mock.patch('sys.warnoptions', [])
+    def test_module_no_spec(self):
+        module = types.ModuleType('test_module')
+        del module.__spec__
+        with mock.patch.dict(sys.modules, {'__main__': module}):
+            self.assertEqual(
+                autoreload.get_child_arguments(),
+                [sys.executable, __file__, 'runserver']
+            )
+
 
 class TestUtilities(SimpleTestCase):
     def test_is_django_module(self):