diff --git a/trunk/src/app/srs_app_server.cpp b/trunk/src/app/srs_app_server.cpp
index cd0849b6d..271a7ad13 100644
--- a/trunk/src/app/srs_app_server.cpp
+++ b/trunk/src/app/srs_app_server.cpp
@@ -586,14 +586,14 @@ srs_error_t SrsServer::initialize(ISrsServerCycle* cycle_handler)
     return err;
 }
 
-int SrsServer::initialize_st()
+srs_error_t SrsServer::initialize_st()
 {
     int ret = ERROR_SUCCESS;
+    srs_error_t err = srs_success;
     
     // init st
     if ((ret = srs_st_init()) != ERROR_SUCCESS) {
-        srs_error("init st failed. ret=%d", ret);
-        return ret;
+        return srs_error_new(ret, "initialize st failed");
     }
     
     // @remark, st alloc segment use mmap, which only support 32757 threads,
@@ -601,11 +601,11 @@ int SrsServer::initialize_st()
     // TODO: FIXME: maybe can use "sysctl vm.max_map_count" to refine.
 #define __MMAP_MAX_CONNECTIONS 32756
     if (_srs_config->get_max_connections() > __MMAP_MAX_CONNECTIONS) {
-        ret = ERROR_ST_EXCEED_THREADS;
         srs_error("st mmap for stack allocation must <= %d threads, "
                   "@see Makefile of st for MALLOC_STACK, please build st manually by "
-                  "\"make EXTRA_CFLAGS=-DMALLOC_STACK linux-debug\", ret=%d", __MMAP_MAX_CONNECTIONS, ret);
-        return ret;
+                  "\"make EXTRA_CFLAGS=-DMALLOC_STACK linux-debug\"", __MMAP_MAX_CONNECTIONS);
+        return srs_error_new(ERROR_ST_EXCEED_THREADS, "%d exceed max %d threads",
+            _srs_config->get_max_connections(), __MMAP_MAX_CONNECTIONS);
     }
     
     // set current log id.
@@ -614,22 +614,20 @@ int SrsServer::initialize_st()
     // initialize the conponents that depends on st.
 #ifdef SRS_AUTO_KAFKA
     if ((ret = srs_initialize_kafka()) != ERROR_SUCCESS) {
-        srs_error("initialize kafka failed, ret=%d", ret);
-        return ret;
+        return srs_error_new(ret, "initialize kafka");
     }
 #endif
     
     // check asprocess.
     bool asprocess = _srs_config->get_asprocess();
     if (asprocess && ppid == 1) {
-        ret = ERROR_SYSTEM_ASSERT_FAILED;
-        srs_error("for asprocess, ppid should never be init(1), ret=%d", ret);
-        return ret;
+        return srs_error_new(ERROR_SYSTEM_ASSERT_FAILED, "ppid=%d illegal for asprocess", ppid);
     }
-    srs_trace("server main cid=%d, pid=%d, ppid=%d, asprocess=%d",
-              _srs_context->get_id(), ::getpid(), ppid, asprocess);
     
-    return ret;
+    srs_trace("server main cid=%d, pid=%d, ppid=%d, asprocess=%d",
+        _srs_context->get_id(), ::getpid(), ppid, asprocess);
+    
+    return err;
 }
 
 int SrsServer::initialize_signal()
diff --git a/trunk/src/app/srs_app_server.hpp b/trunk/src/app/srs_app_server.hpp
index 8a58e9a9d..77be38a8b 100644
--- a/trunk/src/app/srs_app_server.hpp
+++ b/trunk/src/app/srs_app_server.hpp
@@ -302,7 +302,7 @@ public:
      * @remark user must free the cycle handler.
      */
     virtual srs_error_t initialize(ISrsServerCycle* cycle_handler);
-    virtual int initialize_st();
+    virtual srs_error_t initialize_st();
     virtual int initialize_signal();
     virtual int acquire_pid_file();
     virtual int listen();
diff --git a/trunk/src/main/srs_main_server.cpp b/trunk/src/main/srs_main_server.cpp
index 14680244b..3808e1de9 100644
--- a/trunk/src/main/srs_main_server.cpp
+++ b/trunk/src/main/srs_main_server.cpp
@@ -51,7 +51,7 @@ using namespace std;
 
 // pre-declare
 srs_error_t run(SrsServer* svr);
-int run_master(SrsServer* svr);
+srs_error_t run_master(SrsServer* svr);
 void show_macro_features();
 string srs_getenv(const char* name);
 
@@ -342,7 +342,7 @@ void show_macro_features()
     
 #if VERSION_MAJOR > VERSION_STABLE
 #warning "Current branch is unstable."
-    srs_warn("Develop is unstable, please use branch: git checkout %s", VERSION_STABLE_BRANCH);
+    srs_warn("Develop is unstable, please use branch: git checkout -b %s origin/%s", VERSION_STABLE_BRANCH, VERSION_STABLE_BRANCH);
 #endif
     
 #if defined(SRS_PERF_SO_SNDBUF_SIZE) && !defined(SRS_PERF_MW_SO_SNDBUF)
@@ -377,8 +377,8 @@ srs_error_t run(SrsServer* svr)
     
     // if not deamon, directly run master.
     if (!_srs_config->get_deamon()) {
-        if ((ret = run_master(svr)) != ERROR_SUCCESS) {
-            return srs_error_new(ret, "run master");
+        if ((err = run_master(svr)) != srs_success) {
+            return srs_error_wrap(err, "run master");
         }
         return srs_success;
     }
@@ -414,49 +414,50 @@ srs_error_t run(SrsServer* svr)
     // son
     srs_trace("son(deamon) process running.");
     
-    if ((ret = run_master(svr)) != ERROR_SUCCESS) {
-        return srs_error_new(ret, "daemon run master");
+    if ((err = run_master(svr)) != srs_success) {
+        return srs_error_wrap(err, "daemon run master");
     }
     
     return srs_success;
 }
 
-int run_master(SrsServer* svr)
+srs_error_t run_master(SrsServer* svr)
 {
     int ret = ERROR_SUCCESS;
+    srs_error_t err = srs_success;
     
-    if ((ret = svr->initialize_st()) != ERROR_SUCCESS) {
-        return ret;
+    if ((err = svr->initialize_st()) != srs_success) {
+        return srs_error_wrap(err, "initialize st");
     }
     
     if ((ret = svr->initialize_signal()) != ERROR_SUCCESS) {
-        return ret;
+        return srs_error_new(ret, "initialize signal");
     }
     
     if ((ret = svr->acquire_pid_file()) != ERROR_SUCCESS) {
-        return ret;
+        return srs_error_new(ret, "acquire pid file");
     }
     
     if ((ret = svr->listen()) != ERROR_SUCCESS) {
-        return ret;
+        return srs_error_new(ret, "listen");
     }
     
     if ((ret = svr->register_signal()) != ERROR_SUCCESS) {
-        return ret;
+        return srs_error_new(ret, "register signal");
     }
     
     if ((ret = svr->http_handle()) != ERROR_SUCCESS) {
-        return ret;
+        return srs_error_new(ret, "http handle");
     }
     
     if ((ret = svr->ingest()) != ERROR_SUCCESS) {
-        return ret;
+        return srs_error_new(ret, "ingest");
     }
     
     if ((ret = svr->cycle()) != ERROR_SUCCESS) {
-        return ret;
+        return srs_error_new(ret, "main cycle");
     }
     
-    return 0;
+    return err;
 }