_ebuildtester() {
    local cur prev opts
    COMPREPLY=()
    cur="${COMP_WORDS[COMP_CWORD]}"
    prev="${COMP_WORDS[COMP_CWORD-1]}"
    opts="--help --portage-dir --overlay-dir --update --atom --threads"

    if [[ ${cur} == -* || ${COMP_CWORD} -eq 1 ]] ; then
        COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
        return 0
    fi

    case "${prev}" in
        --portage-dir|--overlay-dir)
            COMPREPLY=( $(compgen -o dirnames -A directory ${cur}) )
            ;;
    esac

}
complete -F _ebuildtester ebuildtester