diff -up luaposix-8f8058293efd9654e5fc7f7627a04f4db2b56f8f/posix.lua.lua-52 luaposix-8f8058293efd9654e5fc7f7627a04f4db2b56f8f/posix.lua
--- luaposix-8f8058293efd9654e5fc7f7627a04f4db2b56f8f/posix.lua.lua-52	2013-05-12 21:37:05.201524376 -0400
+++ luaposix-8f8058293efd9654e5fc7f7627a04f4db2b56f8f/posix.lua	2013-05-12 21:43:12.845548551 -0400
@@ -4,6 +4,27 @@ local posix = M
 local bit
 if _VERSION == "Lua 5.1" then bit = require "bit" else bit = require "bit32" end
 
+-- Code extracted from lua-stdlib with minimal modifications
+local list = {
+  sub = function (l, from, to)
+    local r = {}
+    local len = #l
+    from = from or 1
+    to = to or len
+    if from < 0 then
+      from = from + len + 1
+    end
+    if to < 0 then
+      to = to + len + 1
+    end
+    for i = from, to do
+      table.insert (r, l[i])
+    end
+    return r
+  end
+}
+-- end of stdlib code 
+
 --- Create a file.
 -- @param file name of file to create
 -- @param mode permissions with which to create file
@@ -30,7 +51,7 @@ function M.spawn (task, ...)
       task = {"/bin/sh", "-c", task, ...}
     end
     if type (task) == "table" then
-      posix.execp (unpack (task))
+      posix.execp (table.unpack (task))
       -- Only get here if there's an error; kill the fork
       local _, no = posix.errno ()
       posix._exit (no)