问如何使用pbuilder强制更新本地包？

EN

doscanpackages() {
    pushd $1
    dpkg-scanpackages . /dev/null | gzip -9 > Packages.gz
    popd
}

dopbuild() {
    COMMAND=$1
    ARCH=$3

    case "$2" in
        stable|wheezy)
            DIST=debian
            RELEASE=wheezy
            ;;
        testing|jessie)
            DIST=debian
            RELEASE=jessie
            ;;
        unstable|sid)
            DIST=debian
            RELEASE=sid
            ;;
        precise|quantal|raring|saucy|trusty)
            DIST=ubuntu
            RELEASE=$2
            ;;
        *)
            echo "Unknown distribution release : $1"
            exit 1
            ;;
    esac

    case "${DIST}" in
        debian)
            MIRROR=ftp://mirror.ox.ac.uk/debian/
            KEYRING=/usr/share/keyrings/debian-archive-keyring.gpg
            ;;
        ubuntu)
            MIRROR=ftp://archive.ubuntu.com/ubuntu/
            KEYRING=/usr/share/keyrings/ubuntu-archive-keyring.gpg
            ;;
    esac

    REF=${DIST}-${RELEASE}-${ARCH}
    BASETGZ=${PBUILD_DIR}/${REF}.tgz
    OUTPUT=${PBUILD_DIR}/${REF}

    shift
    shift
    shift

    case "${COMMAND}" in
        create|update)
            if [[ -e ${BASETGZ} ]] ; then
                sudo pbuilder --update --override-config --distribution ${RELEASE} --mirror ${MIRROR} --basetgz ${BASETGZ} --debootstrapopts "--keyring=${KEYRING}" --bindmounts "${OUTPUT}" --othermirror "deb file:${OUTPUT} ./"
            else
                mkdir -pv ${PBUILD_IMGDIR}
                sudo pbuilder --create --distribution ${RELEASE} --mirror ${MIRROR} --basetgz ${BASETGZ} --debootstrapopts "--keyring=${KEYRING}" --bindmounts "${OUTPUT}" --othermirror "deb file:${OUTPUT} ./"
            fi
            ;;
        build)
            mkdir -pv ${OUTPUT}
            dopredebbuild ${RELEASE}
            if [[ ! -e builddeb.failed ]] ; then
                (pdebuild --buildresult ${OUTPUT} $@ -- --basetgz ${BASETGZ} --debootstrapopts "--keyring=${KEYRING}" --bindmounts "${OUTPUT}" || touch builddeb.failed) 2>&1 | tee build.log
            fi
            if [[ ! -e builddeb.failed ]] ; then
                doscanpackages ${OUTPUT}
            fi
            dopostdebbuild ${RELEASE}
            ;;
    esac
}