bpo-38912: regrtest logs unraisable exception into sys.__stderr__ (GH-21718)
regrtest_unraisable_hook() temporarily replaces sys.stderr with
sys.__stderr__ to help to display errors when a test captures stderr.
diff --git a/Lib/test/test_regrtest.py b/Lib/test/test_regrtest.py
index 39af0d9..38321e0 100644
--- a/Lib/test/test_regrtest.py
+++ b/Lib/test/test_regrtest.py
@@ -1235,10 +1235,12 @@
re.compile('%s timed out' % testname, re.MULTILINE))
def test_unraisable_exc(self):
- # --fail-env-changed must catch unraisable exception
+ # --fail-env-changed must catch unraisable exception.
+ # The exceptioin must be displayed even if sys.stderr is redirected.
code = textwrap.dedent(r"""
import unittest
import weakref
+ from test.support import captured_stderr
class MyObject:
pass
@@ -1250,9 +1252,11 @@
def test_unraisable_exc(self):
obj = MyObject()
ref = weakref.ref(obj, weakref_callback)
- # call weakref_callback() which logs
- # an unraisable exception
- obj = None
+ with captured_stderr() as stderr:
+ # call weakref_callback() which logs
+ # an unraisable exception
+ obj = None
+ self.assertEqual(stderr.getvalue(), '')
""")
testname = self.create_test(code=code)
@@ -1261,6 +1265,7 @@
env_changed=[testname],
fail_env_changed=True)
self.assertIn("Warning -- Unraisable exception", output)
+ self.assertIn("Exception: weakref callback bug", output)
def test_cleanup(self):
dirname = os.path.join(self.tmptestdir, "test_python_123")