Operation not permitted - /usr/bin/update_rubygems

Question

When I execute on osx El Capitan:

sudo gem update --system  

I got the error:

Updating rubygems-update
ERROR:  While execut         


        

Answer 1

If you have multiple rubygems installs (say from homebrew, rbenv, rvm), to target the update to the default Apple-installed rubygems you may need to use the absolute path /usr/bin/gem to ensure this specific rubygems is updated:

# Note the absolute path to /usr/bin/gem:
sudo /usr/bin/gem update -n /usr/local/bin --system

Answer 2

If you're having issues installing a specific gem after installing ruby through Homebrew (as advised above), try the following:

sudo gem install -n /usr/local/bin GEM_NAME_HERE

Found this thanks to user endoplasmic on this issue thread: https://github.com/sass/sass/issues/1768