commit 2072f9d0ac7a1f080eb9a205b59a6896e5b98fdc
Author: FURUHASHI Sadayuki <frsyuki@users.sourceforge.jp>
Date:   Wed Dec 10 16:48:00 2014 -0800

    Fix error handling at init_system_db_connection() to not use ereport(ERROR).
    
    Because do_child() calls init_system_db_connection() before initializing
    PG_exception_stack, init_system_db_connection() can't use ereport(ERROR).
    A workaround this commit adds is calling child_exit(1) as error handling
    at pool_init_cp() does.

diff --git a/src/protocol/child.c b/src/protocol/child.c
index 5d609ca..735db7a 100644
--- a/src/protocol/child.c
+++ b/src/protocol/child.c
@@ -1753,10 +1753,11 @@ static void init_system_db_connection(void)
 		nRet = system_db_connect();
 		if (nRet || PQstatus(system_db_info->pgconn) != CONNECTION_OK)
 		{
-            ereport(ERROR,
+            /* here can't use ereport(ERROR) because PG_exception_stack is not set yet */
+            ereport(WARNING,
                 (errmsg("failed to make persistent system db connection"),
                      errdetail("system_db_connect failed")));
-
+            child_exit(1);
 		}
 
 		system_db_info->connection = make_persistent_db_connection(pool_config->system_db_hostname,