The Problem
When install gem in Mac OS X Yosemite, I got the following error:
ERROR: While executing gem … (Gem::FilePermissionError) You don’t have write permissions for the /Library/Ruby/Gems/2.0.0 directory.
The Solution
Step 1: Install Rbenv
brew install rbenv ruby-build
echo ‘export PATH=”$HOME/.rbenv/bin:$PATH”’ >> ~/.zshrc
echo ‘eval “$(rbenv init -)”’ >> ~/.zshrc
Note: Modify your ~/.bash_profile instead of ~/.zshrc file if you’re not using zsh.
Step 2: Close your terminal and restart the shell
Step 3: Install Ruby, Set globle and Rehash
rbenv install 2.0.0-p247
rbenv global 2.0.0-p247
rbenv rehash
Step 4: gem install as usual
Now you should get the gem successfully installed!