In this awesome release there are some functions with vararg parameters (...), and they're accessed via the special variable `arg'. Starting with lua 5.1 this `arg' special variable is deprecated. To make awesome 3.3_rc3 working, lua-5.1 has to be compiled with the "deprecated" USE flag. (Another option might be to use lua 5.0 where this syntax was right.)
I've talked to the awesome devs, and in git (and thus the next (pre-) release) they will use lua 5.1 syntax only.
hmm, latest git still needs lua with USE=deprecated. fixed dependency in cvs. thanks.