Getting fish, rbenv & homebrew playing nice together

Installing fish shell

brew install fish

Adding homebrew and rbenv to fish configuration file ~/.config/fish/config.fish

### PATH ###
set default_path /usr/bin /usr/sbin /bin /sbin
set homebrew /usr/local/bin /usr/local/sbin
set brew_rbenv "/usr/local/var/rbenv/shims"
set -gx PATH $homebrew $brew_rbenv $default_path

### Ruby (rbenv) ###
set -gx RBENV_ROOT /usr/local/var/rbenv

Reload the configuration and voilà