As it have been said, the issue comes from a security function of Mac OSX since "El Capitan".
Using the default system Ruby, the install process happens in the /Library/Ruby/Gems/2.0.0
directory which is not available to the user and gives the error.
You can have a look to your Ruby environments parameters with the command
$ gem env
There is an INSTALLATION DIRECTORY and a USER INSTALLATION DIRECTORY. To use the user installation directory instead of the default installation directory, you can use --user-install
parameter instead as using sudo
which is never a recommanded way of doing.
$ gem install myGemName --user-install
There should not be any rights issue anymore in the process. The gems are then installed in the user directory : ~/.gem/Ruby/2.0.0/bin
But to make the installed gems available, this directory should be available in your path. According to the Ruby’s faq, you can add the following line to your ~/.bash_profile
or ~/.bashrc
if which ruby >/dev/null && which gem >/dev/null; then
PATH="$(ruby -rubygems -e 'puts Gem.user_dir')/bin:$PATH"
fi
Then close and reload your terminal or reload your .bash_profile
or .bashrc
(. ~/.bash_profile
)