[fix] Fix logging filters for Python2

src/zc/buildout/buildout.py

@@ -1284,16 +1284,23 @@ class Buildout(DictMixin):
         root_logger = logging.getLogger()
         self._logger = buildout_logger = logging.getLogger('zc.buildout')
 
+        # BBB Python2 (Python3 accepts lambdas as filters)
+        class Filter(object):
+            def __init__(self, callable):
+                self.callable = callable
+            def filter(self, record):
+                return self.callable(record)
+
         # root-specific WARNING handler because setuptools>=65.6.0 logs to root
         root_handler = logging.StreamHandler(sys.stdout)
         root_handler.setLevel(logging.WARNING)
-        root_handler.addFilter(lambda record: record.name == 'root')
+        root_handler.addFilter(Filter(lambda record: record.name == 'root'))
         root_handler.setFormatter(logging.Formatter(generic_log_format))
         root_logger.addHandler(root_handler)
 
         # generic handler for third-party logs
         generic_handler = logging.StreamHandler(sys.stdout)
-        generic_handler.addFilter(lambda record: record.name != 'root')
+        generic_handler.addFilter(Filter(lambda record: record.name != 'root'))
         generic_handler.setFormatter(logging.Formatter(generic_log_format))
         root_logger.addHandler(generic_handler)