gh-128770: raise warnings as errors in test suite - except for test_socket which still logs warnings, and internal test warnings that are now logged

Lib/test/libregrtest/main.py

@@ -642,9 +642,9 @@ def _add_ci_python_opts(self, python_opts, keep_environ):
         if not sys.stdout.write_through:
             python_opts.append('-u')
 
-        # Add warnings filter 'default'
+        # Add warnings filter 'error'
         if 'default' not in sys.warnoptions:
-            python_opts.extend(('-W', 'default'))
+            python_opts.extend(('-W', 'error'))
 
         # Error on bytes/str comparison
         if sys.flags.bytes_warning < 2:

Lib/test/support/__init__.py

@@ -6,6 +6,7 @@
 import contextlib
 import functools
 import inspect
+import logging
 import _opcode
 import os
 import re
@@ -388,7 +389,7 @@ def skip_if_buildbot(reason=None):
     try:
         isbuildbot = getpass.getuser().lower() == 'buildbot'
     except (KeyError, OSError) as err:
-        warnings.warn(f'getpass.getuser() failed {err}.', RuntimeWarning)
+        logging.getLogger(__name__).warning('getpass.getuser() failed %s.', err, exc_info=err)
         isbuildbot = False
     return unittest.skipIf(isbuildbot, reason)
 
@@ -1067,8 +1068,7 @@ def start(self):
         try:
             f = open(self.procfile, 'r')
         except OSError as e:
-            warnings.warn('/proc not available for stats: {}'.format(e),
-                          RuntimeWarning)
+            logging.getLogger(__name__).warning('/proc not available for stats: %s', e, exc_info=e)
             sys.stderr.flush()
             return
 

Lib/test/support/os_helper.py

@@ -1,6 +1,7 @@
 import collections.abc
 import contextlib
 import errno
+import logging
 import os
 import re
 import stat
@@ -378,8 +379,12 @@ def _waitfor(func, pathname, waitall=False):
             # Increase the timeout and try again
             time.sleep(timeout)
             timeout *= 2
-        warnings.warn('tests may fail, delete still pending for ' + pathname,
-                      RuntimeWarning, stacklevel=4)
+        logging.getLogger(__name__).warning(
+            'tests may fail, delete still pending for %s',
+            pathname,
+            stack_info=True,
+            stacklevel=4,
+        )
 
     def _unlink(filename):
         _waitfor(os.unlink, filename)
@@ -494,9 +499,14 @@ def temp_dir(path=None, quiet=False):
         except OSError as exc:
             if not quiet:
                 raise
-            warnings.warn(f'tests may fail, unable to create '
-                          f'temporary directory {path!r}: {exc}',
-                          RuntimeWarning, stacklevel=3)
+            logging.getLogger(__name__).warning(
+                "tests may fail, unable to create temporary directory %r: %s",
+                path,
+                exc,
+                exc_info=exc,
+                stack_info=True,
+                stacklevel=3,
+            )
     if dir_created:
         pid = os.getpid()
     try:
@@ -527,9 +537,15 @@ def change_cwd(path, quiet=False):
     except OSError as exc:
         if not quiet:
             raise
-        warnings.warn(f'tests may fail, unable to change the current working '
-                      f'directory to {path!r}: {exc}',
-                      RuntimeWarning, stacklevel=3)
+        logging.getLogger(__name__).warning(
+            'tests may fail, unable to change the current working directory '
+            'to %r: %s',
+            path,
+            exc,
+            exc_info=exc,
+            stack_info=True,
+            stacklevel=3,
+        )
     try:
         yield os.getcwd()
     finally:

Lib/test/test_decimal.py

@@ -24,6 +24,7 @@
 with the corresponding argument.
 """
 
+import logging
 import math
 import os, sys
 import operator
@@ -5946,8 +5947,9 @@ def tearDownModule():
     if C: C.setcontext(ORIGINAL_CONTEXT[C].copy())
     P.setcontext(ORIGINAL_CONTEXT[P].copy())
     if not C:
-        warnings.warn('C tests skipped: no module named _decimal.',
-                      UserWarning)
+        logging.getLogger(__name__).warning(
+            'C tests skipped: no module named _decimal.'
+        )
     if not orig_sys_decimal is sys.modules['decimal']:
         raise TestFailed("Internal error: unbalanced number of changes to "
                          "sys.modules['decimal'].")

Lib/test/test_hashlib.py

@@ -10,6 +10,7 @@
 import importlib
 import io
 import itertools
+import logging
 import os
 import sys
 import sysconfig
@@ -113,7 +114,11 @@ def _conditional_import_module(self, module_name):
             return importlib.import_module(module_name)
         except ModuleNotFoundError as error:
             if self._warn_on_extension_import and module_name in builtin_hashes:
-                warnings.warn(f'Did a C extension fail to compile? {error}')
+                logging.getLogger(__name__).warning(
+                    'Did a C extension fail to compile? %s',
+                    error,
+                    exc_info=error,
+                )
         return None
 
     def __init__(self, *args, **kwargs):

Lib/test/test_interpreters/utils.py

@@ -1,6 +1,7 @@
 from collections import namedtuple
 import contextlib
 import json
+import logging
 import os
 import os.path
 #import select
@@ -66,8 +67,8 @@ def pack_exception(exc=None):
 def unpack_exception(packed):
     try:
         data = json.loads(packed)
-    except json.decoder.JSONDecodeError:
-        warnings.warn('incomplete exception data', RuntimeWarning)
+    except json.decoder.JSONDecodeError as e:
+        logging.getLogger(__name__).warning('incomplete exception data', exc_info=e)
         print(packed if isinstance(packed, str) else packed.decode('utf-8'))
         return None
     exc = types.SimpleNamespace(**data)

Lib/test/test_pty.py

@@ -135,8 +135,10 @@ def test_openpty(self):
                 new_dim = tty.tcgetwinsize(pty.STDIN_FILENO)
                 self.assertEqual(new_dim, target_dim,
                                  "pty.STDIN_FILENO window size unchanged")
-            except OSError:
-                warnings.warn("Failed to set pty.STDIN_FILENO window size.")
+            except OSError as e:
+                logging.getLogger(__name__).warning(
+                    "Failed to set pty.STDIN_FILENO window size.", exc_info=e,
+                )
                 pass
 
         try:

Lib/test/test_socket.py

@@ -27,6 +27,7 @@
 import threading
 import time
 import traceback
+import warnings
 from weakref import proxy
 try:
     import multiprocessing
@@ -198,6 +199,24 @@ def socket_setdefaulttimeout(timeout):
         socket.setdefaulttimeout(old_timeout)
 
 
+@contextlib.contextmanager
+def downgrade_malformed_data_warning():
+    # This warning happens on macos and win, but does not always happen on linux.
+    if sys.platform not in {"win32", "darwin"}:
+        yield
+        return
+
+    with warnings.catch_warnings():
+        # TODO: gh-110012, we should investigate why this warning is happening
+        # and fix it properly.
+        warnings.filterwarnings(
+            action="always",
+            message="received malformed or improperly-truncated ancillary data",
+            category=RuntimeWarning,
+        )
+        yield
+
+
 HAVE_SOCKET_CAN = _have_socket_can()
 
 HAVE_SOCKET_CAN_ISOTP = _have_socket_can_isotp()
@@ -3946,8 +3965,9 @@ def checkTruncatedArray(self, ancbuf, maxdata, mindata=0):
         # mindata and maxdata bytes when received with buffer size
         # ancbuf, and that any complete file descriptor numbers are
         # valid.
-        msg, ancdata, flags, addr = self.doRecvmsg(self.serv_sock,
-                                                   len(MSG), ancbuf)
+        with downgrade_malformed_data_warning():  # TODO: gh-110012
+            msg, ancdata, flags, addr = self.doRecvmsg(self.serv_sock,
+                                                       len(MSG), ancbuf)
         self.assertEqual(msg, MSG)
         self.checkRecvmsgAddress(addr, self.cli_addr)
         self.checkFlags(flags, eor=True, checkset=socket.MSG_CTRUNC)
@@ -4298,8 +4318,9 @@ def testSingleCmsgTruncInData(self):
         self.serv_sock.setsockopt(socket.IPPROTO_IPV6,
                                   socket.IPV6_RECVHOPLIMIT, 1)
         self.misc_event.set()
-        msg, ancdata, flags, addr = self.doRecvmsg(
-            self.serv_sock, len(MSG), socket.CMSG_LEN(SIZEOF_INT) - 1)
+        with downgrade_malformed_data_warning():  # TODO: gh-110012
+            msg, ancdata, flags, addr = self.doRecvmsg(
+                self.serv_sock, len(MSG), socket.CMSG_LEN(SIZEOF_INT) - 1)
 
         self.assertEqual(msg, MSG)
         self.checkRecvmsgAddress(addr, self.cli_addr)
@@ -4402,9 +4423,10 @@ def testSecondCmsgTruncInData(self):
         self.serv_sock.setsockopt(socket.IPPROTO_IPV6,
                                   socket.IPV6_RECVTCLASS, 1)
         self.misc_event.set()
-        msg, ancdata, flags, addr = self.doRecvmsg(
-            self.serv_sock, len(MSG),
-            socket.CMSG_SPACE(SIZEOF_INT) + socket.CMSG_LEN(SIZEOF_INT) - 1)
+        with downgrade_malformed_data_warning():  # TODO: gh-110012
+            msg, ancdata, flags, addr = self.doRecvmsg(
+                self.serv_sock, len(MSG),
+                socket.CMSG_SPACE(SIZEOF_INT) + socket.CMSG_LEN(SIZEOF_INT) - 1)
 
         self.assertEqual(msg, MSG)
         self.checkRecvmsgAddress(addr, self.cli_addr)