[help] undefined symbol when loading shared object module from embedded lua_state

[Phoenix Sol <phoenix@...>]

I have Lua embedded in a C program, and it raises an error when loading
a script which loads a C module.

I'm compiling the program like this:
gcc uckfuped.c -Wall -O2 -I/usr/local/include -L/usr/local/lib -llua
-ldl -lm -o uckfuped

And when I run it, it tells me:
error loading module 'nixio' from file
'/usr/local/lib/lua/5.1/nixio.so': /usr/local/lib/lua/5.1/nixio.so:
undefined symbol: lua_getmetatable


Hopefully the problem is obvious to someone more experienced? Thanks.