bpo-41898: add caveat on root logger seeing all messages in assertLogs doc (GH-22526) (GH-22540)
(cherry picked from commit 1ed54435268b285964141fb74d47ceaa33ea79ab)
diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index 285bb9e..8a4fd25 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -1088,7 +1088,8 @@
If given, *logger* should be a :class:`logging.Logger` object or a
:class:`str` giving the name of a logger. The default is the root
- logger, which will catch all messages.
+ logger, which will catch all messages that were not blocked by a
+ non-propagating descendent logger.
If given, *level* should be either a numeric logging level or
its string equivalent (for example either ``"ERROR"`` or