Question

I have ruby and gems installed, but when I try to run the update suggested by the ruby on rails download page (http://rubyonrails.org/download) I get an error. Here’s what I’m executing from the root of my user directory:

gem update rails

and the terminal returns:

Updating installed gems
Updating rails
ERROR:  While executing gem ... (Errno::EPERM)
    Operation not permitted - /Library/Ruby/Gems/1.8/gems/json-1.6.3/.gitignore

Answer 1

It’s a permission error.

To make this work do:

sudo gem update rails

BUT

I would highly suggest you use rvm.
OSX comes with an older version of ruby and with RVM you can install
1.9.3 without hosing the built in version of ruby.