[PATCH v2 2/2] kunit: tool: test: Don't rely on implicit working directory change

[David Gow <davidgow@google.com>]

From: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

If no kunitconfig_paths are passed to LinuxSourceTree() it falls back to
DEFAULT_KUNITCONFIG_PATH. This resolution only works when the current
working directory is the root of the source tree. This works by chance
when running the full testsuite through the default unittest runner, as
some tests will change the current working directory as a side-effect of
'kunit.main()'. When running a single testcase or using pytest, which
resets the working directory for each test, this assumption breaks.

Explicitly specify an empty kunitconfig for the affected tests.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: David Gow <davidgow@google.com>
---

Changes since v1:
https://lore.kernel.org/linux-kselftest/20251230-kunit-pytest-v1-2-e2dae0dae200@linutronix.de/
- No-op rebase on top of kselftest/kunit

---
 tools/testing/kunit/kunit_tool_test.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py
index 30ac1cb6c8ed..238a31a5cc29 100755
--- a/tools/testing/kunit/kunit_tool_test.py
+++ b/tools/testing/kunit/kunit_tool_test.py
@@ -477,7 +477,8 @@ class LinuxSourceTreeTest(unittest.TestCase):
 		want_kconfig = kunit_config.Kconfig()
 		want_kconfig.add_entry('NOT_REAL', 'y')
 
-		tree = kunit_kernel.LinuxSourceTree('', kconfig_add=['CONFIG_NOT_REAL=y'])
+		tree = kunit_kernel.LinuxSourceTree('', kunitconfig_paths=[os.devnull],
+						    kconfig_add=['CONFIG_NOT_REAL=y'])
 		self.assertTrue(want_kconfig.is_subset_of(tree._kconfig), msg=tree._kconfig)
 
 	def test_invalid_arch(self):
@@ -489,7 +490,7 @@ class LinuxSourceTreeTest(unittest.TestCase):
 			return subprocess.Popen(['echo "hi\nbye"'], shell=True, text=True, stdout=subprocess.PIPE)
 
 		with tempfile.TemporaryDirectory('') as build_dir:
-			tree = kunit_kernel.LinuxSourceTree(build_dir)
+			tree = kunit_kernel.LinuxSourceTree(build_dir, kunitconfig_paths=[os.devnull])
 			mock.patch.object(tree._ops, 'start', side_effect=fake_start).start()
 
 			with self.assertRaises(ValueError):
-- 
2.52.0.351.gbe84eed79e-goog