diff --git a/lualib/skynet/debug.lua b/lualib/skynet/debug.lua
index 635bdb31..79c51ad1 100644
--- a/lualib/skynet/debug.lua
+++ b/lualib/skynet/debug.lua
@@ -1,6 +1,4 @@
-local io = io
 local table = table
-local debug = debug
 
 return function (skynet, export)
 
diff --git a/lualib/skynet/remotedebug.lua b/lualib/skynet/remotedebug.lua
index 5c1ad9b2..7cfe19eb 100644
--- a/lualib/skynet/remotedebug.lua
+++ b/lualib/skynet/remotedebug.lua
@@ -244,7 +244,9 @@ local function hook_dispatch(dispatcher, resp, fd, channel)
 	func = replace_upvalue(dispatcher, HOOK_FUNC, hook)
 	if func then
 		local function idle()
-			skynet.timeout(10,idle)	-- idle every 0.1s
+			if raw_dispatcher then
+			    skynet.timeout(10,idle)	-- idle every 0.1s
+			end
 		end
 		skynet.timeout(0, idle)
 	end
diff --git a/lualib/snax/hotfix.lua b/lualib/snax/hotfix.lua
index 3a6e4e3e..f56a5072 100644
--- a/lualib/snax/hotfix.lua
+++ b/lualib/snax/hotfix.lua
@@ -1,7 +1,4 @@
 local si = require "snax.interface"
-local io = io
-
-local hotfix = {}
 
 local function envid(f)
 	local i = 1