at the moment there are three vcs packages of tmux on aur. http://aur.archlinux.org/packages.php?K=tmux
tmux-cvs is my package. tmux-git is a tmux developer's synchronisation which doesn't use a separate build directory, but may come in handy because it's git and the commit history is present. tmux-cvs-windowstatus is a patch for an obviously outdated cvs repo, because... the patch is for cmd-set-option.c - though right now the file containing that data is called options-table.c and the patched content has been issue to further changes afaict (being no more window-status-bell-* but window-status-alert-* instead for example). Guess it does not build.
The third one may be deleted imho. And you know what, scratch mine as well... tmux-git is just fine.