Try to update when pkgname or pkgbase match

    pkgdict = parse_pkgbuild(args.path)

    if args.vars:

        pprint(pkgdict)

    pkgname = pkgdict.get("pkgname0", pkgdict.get("pkgbase", None))

    pkgbase = pkgdict.get("pkgbase", None)

    pkgname0 = pkgdict.get("pkgname0", None)

    pkgver = pkgdict.get("pkgver", None)

    # some sanity checks

    if pkgname is None:

        raise BaseError("Unable to detect pkgname in %s" % args.path)

    if pkgname0 is None and pkgbase is None:

        raise BaseError("Unable to detect pkgname/pkgbase in %s" % args.path)

    if pkgver is None:

        raise BaseError("Unable to detect pkgver in %s" % args.path)

    if pkgname not in vctrl.packages:

        raise BaseError("No registered package %s" % pkgname)

    if pkgname0 in vctrl.packages:

        pkgname = pkgname0

    elif pkgbase in vctrl.packages:

        pkgname = pkgbase

    else:

        raise BaseError("No registered package %s" % (pkgbase or pkgname0))

    # redure packge list to the extracted one

    vctrl.reduce_packages((pkgname,))

    # sync if not refused