connecting (pp):~ >su Password: /etc/zshenv: command not found: grep [16] /etc/zshenv: command not found: grep [17] The problem is caused by zshenv having if [ `id -u` -eq 0 ]; then path=(/sbin /usr/sbin) fi in it and after that trying to use grep (which is in /bin).
Fixed in zsh-3.0.5-14