My luarocks installation on OS X comes from the lua installed via
Homebrew. [...]
Error: Your user does not have write permissions in /usr/local
-- you may want to run as a privileged user or use your local tree with --local.
</code>
Homebrew requires /usr/local to be writeable; Homebrew recommend fixes:
sudo chown -R $(whoami) /usr/local
or
sudo chgrp -R admin /usr/local
sudo chmod -R g+w /usr/local
You will need to do one of these to continue using Homebrew. LuaRocks specific options, such as using a local tree, may be fine in general, but you'll still have the Homebrew problem.