Address logger noise

test_tox_pyenv.py

@@ -73,6 +73,13 @@ def test_logs_if_no_pyenv_binary(self):
         self.assertEqual(tox_pyenv.LOG.warning.call_args_list, expected_warn)
 
 
+class TestToxPyenvLogger(unittest.TestCase):
+
+    def test_has_nullhandler(self):
+        handlers = {str(type(handler)) for handler in tox_pyenv.LOG.handlers}
+        self.assertTrue(any('NullHandler' in h for h in handlers))
+
+
 class TestThings(unittest.TestCase):
 
     def test_the_answer(self):

tox_pyenv.py

@@ -49,6 +49,17 @@ def tox_get_python_executable(envconfig):
 
 LOG = logging.getLogger(__name__)
 
+try:
+    # Python 2.7+
+    NullHandler = logging.NullHandler
+except AttributeError:
+    class NullHandler(logging.Handler):
+        """This handler does nothing."""
+        def emit(self, record):
+            pass
+
+LOG.addHandler(NullHandler())
+
 
 class ToxPyenvException(Exception):
 
@@ -66,7 +77,7 @@ class PyenvWhichFailed(ToxPyenvException):
 
 
 @tox_hookimpl
-def tox_get_python_executable(envconfig):
+def tox_get_python_executable(envconfig):  # pylint: disable=R1710
     """Return a python executable for the given python base name.
 
     The first plugin/hook which returns an executable path will determine it.