Mac OS X, fish, brew, rbenv, pyenv work together

Modify /etc/paths for brew path

/usr/local/bin
/usr/local/sbin
/usr/bin
/bin
/usr/sbin
/sbin

Install https://github.com/bpinto/oh-my-fish

Modify ~/.config/fish/config.fish

set -gx RBENV_ROOT /usr/local/opt/rbenv
set -gx PYENV_ROOT /usr/local/opt/pyenv
set fish_path $HOME/.oh-my-fish
set fish_plugins brew rbenv pyenv