fix fedora compilation

core/include/general/debug.h

@@ -32,6 +32,13 @@ class I_Encryptor;
 class I_AgentDetails;
 class I_SignalHandler;
 
+namespace Config
+{
+    enum class Errors;
+}
+
+std::ostream & operator<<(std::ostream &os, const Config::Errors &err);
+
 class Debug
         :
     Singleton::Consume<I_TimeGet>,