Q:

Gem Installs not executing after update system-wide update Arch Linux

When trying to execute sass --watch scss:css inside of a target folder I get returned the message command not found
I know I had sass installed. gem list doesn't show that it's installed anymore. 
I run sudo gem install sass and get the following message:
WARNING: You don't have /root/.gem/ruby/2.3.0/bin in your PATH
         gem executables will not run.

I go to my .bashrc file. I have PATH="$(ruby -e 'print Gem.user_dir')/bin:$PATH" 
I also put it in /etc/bash.bashrc just in case. Nothing Changes.
I go to /etc/profile and insert:
#Setting the GEM_PATH and GEM_HOME variables may not be necessary, check 'gem env' output to verify whether both variables already exist 
 GEM_HOME=$(ls -t -U | ruby -e 'puts Gem.user_dir')
 GEM_PATH=$GEM_HOME
 export PATH=$PATH:$GEM_HOME/bin

I reload profile with . /etc/profile
I try reinstalling sass with sudo gem install sass
Still the same error message. gem list still doesn't show sass
What now??

A:

You are trying to install the gem using sudo, but the system knows the path for your user but not for the sudo user.
To solve this, Add the following line to your ~/.bashrc or .~/zshrc file:
PATH="$(ruby -e 'print Gem.user_dir')/bin:$PATH"

Use the source command to update your profile file or reopen your terminal.
If you use zsh:
source ~/.zshrc

or with bash
source ~/.bashrc

In this way, you will install your gems without sudo, like this example:
gem install rspec 

A:

By default in Arch Linux, when running gem, gems are installed per-user (into ~/.gem/ruby/), instead of system-wide (into /usr/lib/ruby/gems/).
This is considered the best way to manage gems on Arch, because otherwise they might interfere with gems installed by Pacman.
Gems can be installed system wide by running the gem command as root, appended with the --no-user-install flag. This flag can be set as default by replacing --user-install by --no-user-install in /etc/gemrc (system-wide) or ~/.gemrc (per-user, overrides system-wide).
Type in your terminal 
sudo gem install sass --no-user-install

See the arch wiki about ruby gems. Read Installing gems per-user or system-wide

