With OS X EI Capitan, there is a new security function that prevents you from mo

resolved

reason：With OS X EI Capitan, there is a new security function that prevents you from modifying system files called Rootless

1.
sudo gem install -n /usr/local/bin fastlane 
or

2.disable rootless function and install gems after the reboot using:
sudo nvram boot-args="rootless=0"; sudo reboot