Do not configure application root logging on dm_control import

dm_control/_render/__init__.py

@@ -25,9 +25,13 @@
 import collections
 import os
 
-from absl import logging
+import logging
 from dm_control._render import constants
 
+# Import-time status logging must not install a handler on the application root
+# logger. A named stdlib logger leaves logging.basicConfig() available to users.
+_LOGGER = logging.getLogger(__name__)
+
 BACKEND = os.environ.get(constants.MUJOCO_GL)
 
 
@@ -85,24 +89,24 @@ def no_renderer(*args, **kwargs):
     raise RuntimeError(
         'Environment variable {} must be one of {!r}: got {!r}.'
         .format(constants.MUJOCO_GL, sorted(all_names), BACKEND))
-  logging.info('MUJOCO_GL=%s, attempting to import specified OpenGL backend.',
+  _LOGGER.info('MUJOCO_GL=%s, attempting to import specified OpenGL backend.',
                BACKEND)
   Renderer = import_func()
 else:
-  logging.info('MUJOCO_GL is not set, so an OpenGL backend will be chosen '
+  _LOGGER.info('MUJOCO_GL is not set, so an OpenGL backend will be chosen '
                'automatically.')
   # Otherwise try importing them in descending order of priority until
   # successful.
   for names, import_func in _ALL_RENDERERS:
     try:
       Renderer = import_func()
       BACKEND = names[0]
-      logging.info('Successfully imported OpenGL backend: %s', names[0])
+      _LOGGER.info('Successfully imported OpenGL backend: %s', names[0])
       break
     except ImportError:
-      logging.info('Failed to import OpenGL backend: %s', names[0])
+      _LOGGER.info('Failed to import OpenGL backend: %s', names[0])
   if BACKEND is None:
-    logging.info('No OpenGL backend could be imported. Attempting to create a '
+    _LOGGER.info('No OpenGL backend could be imported. Attempting to create a '
                  'rendering context will result in a RuntimeError.')
     Renderer = _no_renderer()
 

dm_control/_render/import_logging_test.py

@@ -0,0 +1,61 @@
+# Copyright 2026 The dm_control Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ============================================================================
+
+"""Regression tests for application logging when importing dm_control."""
+
+import subprocess
+import sys
+
+from absl.testing import absltest
+
+
+class ImportLoggingTest(absltest.TestCase):
+
+  def test_mjcf_import_leaves_root_logger_unconfigured(self):
+    script = """
+import logging
+assert not logging.root.handlers
+from dm_control import mjcf
+assert not logging.root.handlers, logging.root.handlers
+logging.basicConfig(level=logging.INFO, format='APP LOG: %(message)s')
+logging.info('configured after import')
+"""
+    result = subprocess.run(
+        [sys.executable, "-c", script], check=False,
+        capture_output=True, text=True, timeout=30)
+    self.assertEqual(result.returncode, 0, result.stderr)
+    self.assertIn("APP LOG: configured after import", result.stderr)
+
+  def test_mjcf_import_preserves_existing_handler(self):
+    script = """
+import logging
+import sys
+handler = logging.StreamHandler(sys.stderr)
+handler.setFormatter(logging.Formatter('BEFORE: %(message)s'))
+logging.root.addHandler(handler)
+logging.root.setLevel(logging.INFO)
+from dm_control import mjcf
+assert logging.root.handlers == [handler], logging.root.handlers
+logging.info('handler still configured')
+"""
+    result = subprocess.run(
+        [sys.executable, "-c", script], check=False,
+        capture_output=True, text=True, timeout=30)
+    self.assertEqual(result.returncode, 0, result.stderr)
+    self.assertIn("BEFORE: handler still configured", result.stderr)
+
+
+if __name__ == "__main__":
+  absltest.main()

dm_control/mujoco/wrapper/mjbindings/__init__.py

@@ -16,20 +16,22 @@
 """Import core names of MuJoCo ctypes bindings."""
 
 
-from absl import logging
+import logging
 
 from dm_control.mujoco.wrapper.mjbindings import constants
 from dm_control.mujoco.wrapper.mjbindings import enums
 from dm_control.mujoco.wrapper.mjbindings import sizes
 
+_LOGGER = logging.getLogger(__name__)
+
 # Internal analytics import.
 
 # pylint: disable=g-import-not-at-top
 try:
   from dm_control.mujoco.wrapper.mjbindings import functions
   from dm_control.mujoco.wrapper.mjbindings.functions import mjlib
-  logging.info('MuJoCo library version is: %s', mjlib.mj_versionString())
+  _LOGGER.info('MuJoCo library version is: %s', mjlib.mj_versionString())
   # Internal analytics.
 except (IOError, OSError):
-  logging.warning('mjbindings failed to import mjlib and other functions. '
+  _LOGGER.warning('mjbindings failed to import mjlib and other functions. '
                   'libmujoco.so may not be accessible.')