Logging propagation (#10092)

* Enable propagation by default

* Document enable/disable default handler

docs/source/main_classes/logging.rst

@@ -65,6 +65,10 @@ Other functions
 
 .. autofunction:: transformers.logging.get_logger
 
+.. autofunction:: transformers.logging.enable_default_handler
+
+.. autofunction:: transformers.logging.disable_default_handler
+
 .. autofunction:: transformers.logging.enable_explicit_format
 
 .. autofunction:: transformers.logging.reset_format

src/transformers/utils/logging.py

@@ -85,7 +85,6 @@ def _configure_library_root_logger() -> None:
         library_root_logger = _get_library_root_logger()
         library_root_logger.addHandler(_default_handler)
         library_root_logger.setLevel(_get_default_logging_level())
-        library_root_logger.propagate = False
 
 
 def _reset_library_root_logger() -> None: