Check the build mechanisms: Do they support a "-rc" suffix?

configure.in

@@ -27,7 +27,7 @@ dnl
 dnl When changing the major version number please also check the switch
 dnl statement in mysqlbinlog::check_master_version().  You may also need
 dnl to update version.c in ndb.
-AC_INIT([MySQL Server], [5.5.6-m3], [], [mysql])
+AC_INIT([MySQL Server], [5.5.6-rc], [], [mysql])
 
 AC_CONFIG_SRCDIR([sql/mysqld.cc])
 AC_CANONICAL_SYSTEM