[mod] the environment variable SEARX_DEBUG can override the general.debug value in settings.yml

searx/__init__.py

 with open(settings_path) as settings_yaml:
     settings = load(settings_yaml)
 
-if settings.get('general', {}).get('debug'):
+'''
+enable debug if
+the environnement variable SEARX_DEBUG is 1 or true
+(whatever the value in settings.yml)
+or general.debug=True in settings.yml
+
+disable debug if
+the environnement variable SEARX_DEBUG is 0 or false
+(whatever the value in settings.yml)
+or general.debug=False in settings.yml
+'''
+searx_debug_env = environ.get('SEARX_DEBUG', '').lower()
+if searx_debug_env == 'true' or searx_debug_env == '1':
+    searx_debug = True
+elif searx_debug_env == 'false' or searx_debug_env == '0':
+    searx_debug = False
+else:
+    searx_debug = settings.get('general', {}).get('debug')
+
+if searx_debug:
     logging.basicConfig(level=logging.DEBUG)
 else:
     logging.basicConfig(level=logging.WARNING)

searx/webapp.py

 )
 from flask_babel import Babel, gettext, format_date, format_decimal
 from flask.json import jsonify
-from searx import settings, searx_dir
+from searx import settings, searx_dir, searx_debug
 from searx.engines import (
     categories, engines, get_engines_stats, engine_shortcuts
 )
 
 def run():
     app.run(
-        debug=settings['general']['debug'],
-        use_debugger=settings['general']['debug'],
+        debug=searx_debug,
+        use_debugger=searx_debug,
         port=settings['server']['port'],
         host=settings['server']['bind_address'],
         threaded=True