When install sudo gem install sass
ERROR: While executing gem ... (Gem::FilePermissionError)
You don't have write permissions for the /usr/bin directory.

reinstall compass fix it
sudo gem install -n /usr/local/bin sass

Maybe it's your compass has hung up, you can execute: sudo gem install compass to fix it.

Thanks @Mttylzq

Solved this problem:
sudo gem install -n /usr/local/bin sass

I have read that using sudo to install gems is dangerous in that it can overwrite your hard drive or publish sensitive information to the internet:
https://github.com/calabash/calabash-ios/wiki/Best-Practice%3A--Never-install-gems-with-sudo

Does anyone know if this is still true ?

Installing it elsewhere is not "solving"??

Installing it elsewhere is not "solving"??

With the way MacOS is now, this is as solved as it's gonna get

With the way MacOS is now, this is as solved as it's gonna get

@sean256 What is it about the MacOS that makes you have to install in a different directory?