ERROR: While executing gem … (Errno::EPERM) Operation not permitted [duplicate]
I found the answer on SASS issues: https://github.com/sass/sass/issues/1768 Since OSX el Capitan there is a new security function that prevents you from modifying system files called Rootless. So you have 2 options: If you install gems on /usr/local/bin there will be no problem because rootless doesn’t affect this path. sudo gem install -n /usr/local/bin GEM_NAME_HERE