PYTHON-5292 - Debug logs should only print on failed tests

.evergreen/scripts/run_tests.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import json
-import logging
 import os
 import platform
 import shutil
@@ -173,9 +172,6 @@ def run() -> None:
         handle_aws_lambda()
         return
 
-    if os.environ.get("DEBUG_LOG"):
-        TEST_ARGS.extend(f"-o log_cli_level={logging.DEBUG} -o log_cli=1".split())
-
     # Run local tests.
     ret = pytest.main(TEST_ARGS + sys.argv[1:])
     if ret != 0:

.evergreen/scripts/setup_tests.py

@@ -465,9 +465,7 @@ def handle_test_env() -> None:
         UV_ARGS.append(f"--group {framework}")
 
     else:
-        # Use --capture=tee-sys so pytest prints test output inline:
-        # https://docs.pytest.org/en/stable/how-to/capture-stdout-stderr.html
-        TEST_ARGS = f"-v --capture=tee-sys --durations=5 {TEST_ARGS}"
+        TEST_ARGS = f"-v --durations=5 {TEST_ARGS}"
         TEST_SUITE = TEST_SUITE_MAP.get(test_name)
         if TEST_SUITE:
             TEST_ARGS = f"-m {TEST_SUITE} {TEST_ARGS}"

CONTRIBUTING.md

@@ -351,11 +351,11 @@ If you are running one of the `no-responder` tests, omit the `run-server` step.
 
 ## Enable Debug Logs
 
-- Use `-o log_cli_level="DEBUG" -o log_cli=1` with `just test` or `pytest`.
-- Add `log_cli_level = "DEBUG` and `log_cli = 1` to the `tool.pytest.ini_options` section in `pyproject.toml` for Evergreen patches or to enable debug logs by default on your machine.
-- You can also set `DEBUG_LOG=1` and run either `just setup-tests` or `just-test`.
+- Use `-o log_cli_level="DEBUG" -o log_cli=1` with `just test` or `pytest` to output all debug logs to the terminal. **Warning**: This will output a huge amount of logs.
+- Add `log_cli_level = "DEBUG` to the `tool.pytest.ini_options` section in `pyproject.toml` to enable debug logs in this manner by default on your machine.
+- Set `DEBUG_LOG=1` and run `just setup-tests`, `just-test`, or `pytest` to enable debug logs only for failed tests.
 - Finally, you can use `just setup-tests --debug-log`.
-- For evergreen patch builds, you can use `evergreen patch --param DEBUG_LOG=1` to enable debug logs for the patch.
+- For evergreen patch builds, you can use `evergreen patch --param DEBUG_LOG=1` to enable debug logs for failed tests in the patch.
 
 ## Adding a new test suite
 

pymongo/logger.py

@@ -15,6 +15,7 @@
 
 import enum
 import logging
+import logging.handlers
 import os
 import warnings
 from typing import Any
@@ -95,6 +96,13 @@ class _SDAMStatusMessage(str, enum.Enum):
     ConnectionCheckOutFailedReason.TIMEOUT: "Connection exceeded the specified timeout",
 }
 
+if os.environ.get("DEBUG_LOG"):
+    _COMMAND_LOGGER.setLevel(logging.DEBUG)
+    _SERVER_SELECTION_LOGGER.setLevel(logging.DEBUG)
+    _CONNECTION_LOGGER.setLevel(logging.DEBUG)
+    _CLIENT_LOGGER.setLevel(logging.DEBUG)
+    _SDAM_LOGGER.setLevel(logging.DEBUG)
+
 
 def _log_client_error() -> None:
     # This is called from a daemon thread so check for None to account for interpreter shutdown.

pyproject.toml

@@ -98,6 +98,7 @@ minversion = "7"
 addopts = ["-ra", "--strict-config", "--strict-markers", "--junitxml=xunit-results/TEST-results.xml", "-m default or default_async"]
 testpaths = ["test"]
 log_cli_level = "INFO"
+log_cli = true
 faulthandler_timeout = 1500
 asyncio_default_fixture_loop_scope = "session"
 xfail_strict = true

test/asynchronous/test_client.py

@@ -34,7 +34,7 @@
 import time
 import uuid
 from typing import Any, Iterable, Type, no_type_check
-from unittest import mock
+from unittest import mock, skipIf
 from unittest.mock import patch
 
 import pytest
@@ -629,6 +629,7 @@ def test_detected_environment_logging(self, mock_get_hosts):
             logs = [record.getMessage() for record in cm.records if record.name == "pymongo.client"]
             self.assertEqual(len(logs), 7)
 
+    @skipIf(os.environ.get("DEBUG_LOG"), "Enabling debug logs breaks this test")
     @patch("pymongo.asynchronous.srv_resolver._SrvResolver.get_hosts")
     async def test_detected_environment_warning(self, mock_get_hosts):
         with self._caplog.at_level(logging.WARN):

test/test_client.py

@@ -34,7 +34,7 @@
 import time
 import uuid
 from typing import Any, Iterable, Type, no_type_check
-from unittest import mock
+from unittest import mock, skipIf
 from unittest.mock import patch
 
 import pytest
@@ -622,6 +622,7 @@ def test_detected_environment_logging(self, mock_get_hosts):
             logs = [record.getMessage() for record in cm.records if record.name == "pymongo.client"]
             self.assertEqual(len(logs), 7)
 
+    @skipIf(os.environ.get("DEBUG_LOG"), "Enabling debug logs breaks this test")
     @patch("pymongo.synchronous.srv_resolver._SrvResolver.get_hosts")
     def test_detected_environment_warning(self, mock_get_hosts):
         with self._caplog.at_level(logging.WARN):