fix bug where the error of a missing config.yml file was not handled;

host/Host.cpp

@@ -114,10 +114,16 @@ Host::~Host()
 /// <returns>Zero if successful, otherwise error occurred.</returns>
 int Host::run()
 {
-    bool ret = yaml::Parse(m_conf, m_confFile.c_str());
+    bool ret = false;
+    try {
+        ret = yaml::Parse(m_conf, m_confFile.c_str());
         if (!ret) {
             ::fatal("cannot read the configuration file, %s\n", m_confFile.c_str());
         }
+    }
+    catch (yaml::OperationException e) {
+        ::fatal("cannot read the configuration file, %s", e.message());
+    }
 
     bool m_daemon = m_conf["daemon"].as<bool>(false);
     if (m_daemon && g_foreground)