Prefer _pkgvere to pkgver when updating

def pkgbuild_set_version(path, version, reset=True):

    '''

    Change PKGBUILD pkgver to version

    If reset is True, pkgrel will be set to 1

    Change PKGBUILD $pkgver to version

    if a variable $_pkgver is present, this one will be updated instead of $pkgver

    If reset is True, $pkgrel will be set to 1

    '''

    wspces = "[ \t\r\f\v]"

    data = open(path, "r").read()

    data = re.sub("pkgver=.*", "pkgver=%s" % version, data)

    # prefer to replace $_pkgver

    var = "pkgver" if re.search("^%s*_pkgver=" % wspces, data,

        re.MULTILINE) is None else "_pkgver"

    data = re.sub("^(%s*%s=).*$" % (wspces, var),

        "\g<1>%s" % version, data, flags=re.MULTILINE)

    if reset:

        data = re.sub("pkgrel=.*", "pkgrel=1", data)

        data = re.sub("^(%s*pkgrel=).*" % wspces, "\g<1>1", data,

            flags=re.MULTILINE)

    open(path, "w").write(data)

def pkgbuild_update_checksums(path):