请教一个skynet启动的问题

[ericzhanchina]

原来一直用的skynet 1.5版本，现在想升级到最新的1.6版本，所以把最新版本下载下来，编译后，./skynet examples/config可以启动。

于是想保留原来的老版本，直接把新的代码放到项目的根目录下的skyne160目录，然后修改配置文件，这样可以保留原来的1.5版本，同时可以用1.6

root        =   "./"
skynet      =   root.."skynet160/"
thread      =   1                                                   -- worker thread equals cpus            
logger      =   root.."/log/all.log"
logservice  =   "logger"
logpath     =   "./log/"
loggroup    =   "log"
log_debug   =   true
harbor      =   0                                                   -- standalone with cluster mode
start       =   "clusterlog"                                              -- enterance
bootstrap   =   "snlua bootstrap"	                                -- The service for bootstrap
lua_path    =   root.."libs/lua/?.lua;"..                           -- lua lib from skynet and tok project
                root.."share/?.lua;"..
                root.."game/?.lua;"..
                skynet.."lualib/?.lua;"
luaservice  =   root.."service/?.lua;"..                            -- lua service from skynet and tok project  
                skynet.."service/?.lua;"
lualoader   =   skynet.."lualib/loader.lua"
cpath       =   skynet.."cservice/?.so"                             -- c service for skynet
lua_cpath   =   root.."libs/c/?.so;".. skynet.."luaclib/?.so"       -- for the c lib used in project
cluster     =   root.."service/tok_cluster_local.lua"
servicename =   "logd"
nodename    =   "log"
debug_port  =   8804

这个是一个进程的配置文件，结果启动的时候直接就报错了。

starting the tok log server
SKYNET_ENV = local
try open snlua failed : ./skynet160/cservice/snlua.so: undefined symbol: lua_closethread
the tok log server starts

求指点，哪里会有问题呢？