Enable logging through Python logging module

changelog.d/2974.change.rst

@@ -0,0 +1 @@
+Setuptools now relies on the Python logging infrastructure to log messages. Instead of using ``distutils.log.*``, use ``logging.getLogger(name).*``.

setuptools/__init__.py

@@ -18,6 +18,7 @@
 from setuptools.dist import Distribution
 from setuptools.depends import Require
 from . import monkey
+from . import logging
 
 
 __all__ = [
@@ -149,6 +150,7 @@ def finalize_options(self):
 
 def setup(**attrs):
     # Make sure we have any requirements needed to interpret 'attrs'.
+    logging.configure()
     _install_setup_requires(attrs)
     return distutils.core.setup(**attrs)
 

setuptools/logging.py

@@ -0,0 +1,30 @@
+import sys
+import logging
+import distutils.log
+from . import monkey
+
+
+def _not_warning(record):
+    return record.levelno < logging.WARNING
+
+
+def configure():
+    """
+    Configure logging to emit warning and above to stderr
+    and everything else to stdout. This behavior is provided
+    for compatibilty with distutils.log but may change in
+    the future.
+    """
+    err_handler = logging.StreamHandler()
+    err_handler.setLevel(logging.WARNING)
+    out_handler = logging.StreamHandler(sys.stdout)
+    out_handler.addFilter(_not_warning)
+    handlers = err_handler, out_handler
+    logging.basicConfig(
+        format="{message}", style='{', handlers=handlers, level=logging.DEBUG)
+    monkey.patch_func(set_threshold, distutils.log, 'set_threshold')
+
+
+def set_threshold(level):
+    logging.root.setLevel(level*10)
+    return set_threshold.unpatched(level)