Fixed #18845 -- Do not swallow AttributeErrors when running commands

django/core/management/__init__.py

@@ -103,10 +103,12 @@ def get_commands():
         _commands = dict([(name, 'django.core') for name in find_commands(__path__[0])])
 
         # Find the installed apps
-        try:
         from django.conf import settings
+        try:
             apps = settings.INSTALLED_APPS
-        except (AttributeError, ImproperlyConfigured):
+        except ImproperlyConfigured:
+            # Still useful for commands that do not require functional settings,
+            # like startproject or help
             apps = []
 
         # Find and load the management module for each installed app.

tests/regressiontests/admin_scripts/tests.py

@@ -982,13 +982,11 @@ class ManageMultipleSettings(AdminScriptTestCase):
         self.assertNoOutput(err)
         self.assertOutput(out, "EXECUTE:NoArgsCommand")
 
+
 class ManageSettingsWithImportError(AdminScriptTestCase):
     """Tests for manage.py when using the default settings.py file
     with an import error. Ticket #14130.
     """
-    def setUp(self):
-        self.write_settings_with_import_error('settings.py')
-
     def tearDown(self):
         self.remove_settings('settings.py')
 
@@ -1004,12 +1002,27 @@ class ManageSettingsWithImportError(AdminScriptTestCase):
             settings_file.write('# The next line will cause an import error:\nimport foo42bar\n')
 
     def test_builtin_command(self):
-        "import error: manage.py builtin commands shows useful diagnostic info when settings with import errors is provided"
+        """
+        import error: manage.py builtin commands shows useful diagnostic info
+        when settings with import errors is provided
+        """
+        self.write_settings_with_import_error('settings.py')
         args = ['sqlall', 'admin_scripts']
         out, err = self.run_manage(args)
         self.assertNoOutput(out)
         self.assertOutput(err, "No module named foo42bar")
 
+    def test_builtin_command_with_attribute_error(self):
+        """
+        manage.py builtin commands does not swallow attribute errors from bad settings (#18845)
+        """
+        self.write_settings('settings.py', sdict={'BAD_VAR': 'INSTALLED_APPS.crash'})
+        args = ['collectstatic', 'admin_scripts']
+        out, err = self.run_manage(args)
+        self.assertNoOutput(out)
+        self.assertOutput(err, "AttributeError: 'list' object has no attribute 'crash'")
+
+
 class ManageValidate(AdminScriptTestCase):
     def tearDown(self):
         self.remove_settings('settings.py')