Fixed #32227 -- Prevented crash when setUpTestData() errors with --debug-sql.

Thanks Mariusz Felisiak for the report.

django/test/runner.py

@@ -38,6 +38,7 @@ class DebugSQLTextTestResult(unittest.TextTestResult):
     def __init__(self, stream, descriptions, verbosity):
         self.logger = logging.getLogger('django.db.backends')
         self.logger.setLevel(logging.DEBUG)
+        self.debug_sql_stream = None
         super().__init__(stream, descriptions, verbosity)
 
     def startTest(self, test):
@@ -56,8 +57,13 @@ class DebugSQLTextTestResult(unittest.TextTestResult):
 
     def addError(self, test, err):
         super().addError(test, err)
+        if self.debug_sql_stream is None:
+            # Error before tests e.g. in setUpTestData().
+            sql = ''
+        else:
             self.debug_sql_stream.seek(0)
-        self.errors[-1] = self.errors[-1] + (self.debug_sql_stream.read(),)
+            sql = self.debug_sql_stream.read()
+        self.errors[-1] = self.errors[-1] + (sql,)
 
     def addFailure(self, test, err):
         super().addFailure(test, err)

tests/test_runner/test_debug_sql.py

@@ -25,6 +25,14 @@ class TestDebugSQL(unittest.TestCase):
             Person.objects.filter(first_name='error').count()
             raise Exception
 
+    class ErrorSetUpTestDataTest(TestCase):
+        @classmethod
+        def setUpTestData(cls):
+            raise Exception
+
+        def runTest(self):
+            pass
+
     class PassingSubTest(TestCase):
         def runTest(self):
             with self.subTest():
@@ -107,3 +115,22 @@ class TestDebugSQL(unittest.TestCase):
             '''FROM "test_runner_person" WHERE '''
             '''"test_runner_person"."first_name" = 'subtest-pass';'''),
     ]
+
+    def test_setupclass_exception(self):
+        runner = DiscoverRunner(debug_sql=True, verbosity=0)
+        suite = runner.test_suite()
+        suite.addTest(self.ErrorSetUpTestDataTest())
+        old_config = runner.setup_databases()
+        stream = StringIO()
+        runner.test_runner(
+            verbosity=0,
+            stream=stream,
+            resultclass=runner.get_resultclass(),
+        ).run(suite)
+        runner.teardown_databases(old_config)
+        output = stream.getvalue()
+        self.assertIn(
+            'ERROR: setUpClass '
+            '(test_runner.test_debug_sql.TestDebugSQL.ErrorSetUpTestDataTest)',
+            output,
+        )