diff --git a/swh/core/config.py b/swh/core/config.py
--- a/swh/core/config.py
+++ b/swh/core/config.py
@@ -4,6 +4,7 @@
 # See top-level LICENSE file for more information
 
 import configparser
+import logging
 import os
 import yaml
 
@@ -84,6 +85,7 @@
 
     yml_file = base_config_path + '.yml'
     if exists_accessible(yml_file):
+        logging.debug('Using config file %s', yml_file)
         with open(yml_file) as f:
             return yaml.safe_load(f)
 
@@ -92,7 +94,10 @@
         config = configparser.ConfigParser()
         config.read(ini_file)
         if 'main' in config._sections:
+            logging.debug('Using config file %s', ini_file)
             return config._sections['main']
+        else:
+            logging.debug('Ignoring config file %s (no [main])', ini_file)
 
     return {}