tools (common/dynamic_import): log a warning if bridge can't be imported

sat/tools/common/dynamic_import.py

@@ -1,7 +1,6 @@
 #!/usr/bin/env python3
 
-
-# SàT: a XMPP
+# SàT: an XMPP client
 # Copyright (C) 2009-2020 Jérôme Poisson (goffi@goffi.org)
 
 # This program is free software: you can redistribute it and/or modify
@@ -20,6 +19,10 @@
 """ tools dynamic import """
 
 from importlib import import_module
+from sat.core.log import getLogger
+
+
+log = getLogger(__name__)
 
 
 def bridge(name, module_path="sat.bridge"):
@@ -34,6 +37,7 @@ def bridge(name, module_path="sat.bridge"):
     except ImportError:
         try:
             bridge_module = import_module(module_path + "." + name + "_bridge")
-        except ImportError:
+        except ImportError as e:
+            log.warning(f"Can't import bridge {name!r}: {e}")
             bridge_module = None
     return bridge_module