From the docs, the process is:
$ git clone git://github.com/n1k0/casperjs.git
$ cd casperjs
$ ln -sf `pwd`/bin/casperjs /usr/local/bin/casperjs
After doing this, my error is as follows. What am I doing wrong?
$ casperjs --version
-bash: /usr/local/bin/casperjs: is a directory