How to use the pkgbuilder.DS.log.info function in pkgbuilder

print(':: ' + _('Fetching package information...'))
            for u in args.userfetch:
                try:
                    tofetch += pkgbuilder.utils.msearch(u)
                except pkgbuilder.exceptions.AURError as e:
                    print(_('Error while processing {0}: {1}').format(u, e))

            pkgbuilder.build.fetch_runner(tofetch, preprocessed=True)
            if quit:
                exit(0)

        # If we didn't quit, we should build the packages.
        if pkgnames:
            DS.root_crash()

            DS.log.info('Starting build...')
            toinstall = []
            sigs = []
            tovalidate = set(pkgnames)

            for pkgname in pkgnames:
                try:
                    DS.log.info('Building {0}'.format(pkgname))
                    out = pkgbuilder.build.auto_build(pkgname, args.depcheck,
                                                      args.pkginst, pkgnames)
                    if out:
                        toinstall += out[1][0]
                        sigs += out[1][1]
                except PBException as e:
                    DS.fancy_error(str(e))
                    if e.exit:
                        exit(1)

user_chdir = DS.config.get('extras', 'chdir').strip()

        if user_chdir:
            DS.log.debug('Changing directory to %s (via config)', user_chdir)
            os.makedirs(user_chdir, exist_ok=True)
            os.chdir(user_chdir)
        elif DS.pacman:
            DS.log.debug('-S passed, building in /tmp/.')
            path = '/tmp/pkgbuilder-{0}'.format(str(DS.uid))
            if not os.path.exists(path):
                os.mkdir(path)
            os.chdir(path)

        if args.upgrade:
            DS.root_crash()
            DS.log.info('Starting upgrade...')
            dodowngrade = args.upgrade > 1
            ignorelist = []
            for i in (args.ignorelist or []):
                # `pacman -Syu --ignore a,b --ignore c` → ignores a, b, c
                ignorelist.extend(i.split(','))
            upnames = pkgbuilder.upgrade.auto_upgrade(
                dodowngrade, DS.vcsupgrade, DS.fetch, ignorelist)
            pkgnames = upnames + pkgnames

        if DS.fetch and pkgnames:
            pkgbuilder.build.fetch_runner(pkgnames)
            if quit:
                exit(0)

        if args.userfetch:
            tofetch = []

except NetworkError as e:
        DS.fancy_error(str(e))
        # TRANSLATORS: do not translate the word 'requests'.
        DS.fancy_error(_('PKGBUILDer (or the requests library) had '
                         'problems with fulfilling an HTTP request.'))
        if e.exit:
            exit(1)
    except PBException as e:
        DS.fancy_error(str(e))
        if e.exit:
            exit(1)
    except KeyboardInterrupt:
        pkgbuilder.DS.fancy_error(pkgbuilder.DS.inttext)
        exit(130)

    DS.log.info('Quitting peacefully.')

if args.finst:
            pkgbuilder.build.install(pkgnames, [], False)
            if quit:
                exit(0)

        if args.pac:
            DS.log.debug('-S passed, building in /tmp/.')
            path = '/tmp/pkgbuilder-{0}'.format(str(DS.uid))
            if not os.path.exists(path):
                os.mkdir(path)
            os.chdir(path)

        if args.upgrade > 0:
            DS.root_crash()
            DS.log.info('Starting upgrade...')
            dodowngrade = args.upgrade > 1
            upnames = pkgbuilder.upgrade.auto_upgrade(dodowngrade, args.vcsup)
            pkgnames = upnames + pkgnames

        if args.fetch:
            pkgbuilder.build.fetch_runner(pkgnames)
            if quit:
                exit(0)

        if args.userfetch:
            tofetch = []
            print(':: ' + _('Fetching package information...'))
            for u in args.userfetch:
                try:
                    tofetch += pkgbuilder.utils.msearch(u)
                except pkgbuilder.exceptions.AURError as e:

else:
            args = parser.parse_args()

        DS.pacman = args.pac
        DS.cleanup = args.cleanup
        pkgnames = args.pkgnames

        if args.aur4:
            pkgbuilder.aur.AUR.base = 'https://aur4.archlinux.org'

        if args.debug:
            DS.debugmode(nochange=True)
            DS.log.info('*** PKGBUILDer v{0}'.format(__version__))
            DS.log.debug('*** debug output on.')

        DS.log.info('Arguments parsed.  {0}'.format(args.__dict__))

        if 'VIRTUAL_ENV' in os.environ:
            DS.log.error("virtualenv detected, exiting.")
            DS.fancy_error(_("PKGBUILDer cannot work in a virtualenv, "
                             "exiting."))
            exit(83)

        if not args.color:
            DS.colorsoff()
            DS.log.debug('Colors turned off.')

        if args.info:
            DS.log.debug('Showing info...')

            pkgs = pkgbuilder.utils.info(pkgnames)
            foundnames = [i.name for i in pkgs]

print(':: ' + _('Fetching package information...'))
            for u in args.userfetch:
                try:
                    tofetch += pkgbuilder.utils.msearch(u)
                except pkgbuilder.exceptions.AURError as e:
                    print(_('Error while processing {0}: {1}').format(u, e))

            pkgbuilder.build.fetch_runner(tofetch, preprocessed=True)
            if quit:
                exit(0)

        # If we didn't quit, we should build the packages.
        if pkgnames:
            DS.root_crash()

            DS.log.info('Starting build...')
            toinstall = []
            sigs = []
            tovalidate = set(pkgnames)

            for pkgname in pkgnames:
                try:
                    DS.log.info('Building {0}'.format(pkgname))
                    out = pkgbuilder.build.auto_build(pkgname, DS.depcheck,
                                                      DS.pkginst, pkgnames,
                                                      DS.edit_pkgbuild)
                    if out:
                        toinstall += out[1][0]
                        sigs += out[1][1]
                except PBException as e:
                    DS.fancy_error(str(e))
                    if e.exit:

def save(self, filename=None):
        """Save a transaction file."""
        if filename is not None:
            self.filename = filename
        if self.filename:
            with open(self.filename, 'w+') as fh:
                fh.write(self.tojson())
            DS.log.info("Transaction saved: {0}".format(self.filename))

def build_runner(pkgname, performdepcheck=True,
                 pkginstall=True, pkgbuild_edit=False):
    """A build function, which actually links to others.

    DO NOT use it unless you re-implement auto_build!

    """
    pkg = None
    try:
        pkg = pkgbuilder.utils.info([pkgname])[0]
    except IndexError:
        DS.log.info('{0} not found in the AUR, checking in repositories'.format(
            pkgname))
        syncpkgs = []
        for j in [i.pkgcache for i in DS.pyc.get_syncdbs()]:
            syncpkgs.append(j)
        syncpkgs = functools.reduce(lambda x, y: x + y, syncpkgs)
        abspkg = pyalpm.find_satisfier(syncpkgs, pkgname)
        if abspkg:  # abspkg can be None or a pyalpm.Package object.
            pkg = pkgbuilder.package.ABSPackage.from_pyalpm(abspkg)
            subpackages = [pkg.name]  # no way to get it
    if not pkg:
        raise pkgbuilder.exceptions.PackageNotFoundError(pkgname, 'build')

    DS.fancy_msg(_('Building {0}...').format(pkg.name))
    pkgbuilder.utils.print_package_search(pkg,
                                          prefix=DS.colors['blue'] +
                                          '  ->' + DS.colors['all_off'] +