Web lists-archives.com

Impossible to migrate to buster

I have updated my sources.list from stretch :

root@server:~# cat  /etc/apt/sources.list

deb http://debian.proxad.net/debian/ buster main contrib
deb-src http://debian.proxad.net/debian/ buster main contrib

deb http://security.debian.org buster/updates main contrib
deb-src http://security.debian.org buster/updates main contrib

# buster-updates, previously known as 'volatile'
deb http://debian.proxad.net/debian/ buster-updates main contrib
deb-src http://debian.proxad.net/debian/ buster-updates main contrib
root@server:~#apt update

root@server:~# apt update
Hit:1 http://debian.proxad.net/debian buster InRelease
Hit:2 http://security.debian.org buster/updates InRelease
Hit:3 http://debian.proxad.net/debian buster-updates InRelease
Reading package lists... Done
Building dependency tree
Reading state information... Done
295 packages can be upgraded. Run 'apt list --upgradable' to see them.
root@server:~# apt upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:   dh-python libbind9-140 libdns162 libgmime-2.6-0 libicu57 libisc160 libisccc140 libisccfg140 liblwres141 libnotmuch4 libperl5.24   libpython3.5-minimal libpython3.5-stdlib libtalloc2 python3-distutils python3-lib2to3 python3.5 python3.5-minimal rename sgml-base
  tcpd xml-core
Use 'apt autoremove' to remove them.
The following NEW packages will be installed:
  apparmor dirmngr e2fsprogs-l10n fdisk gcc-8-base gnupg-l10n gnupg-utils gpg gpg-agent gpg-wks-client gpg-wks-server gpgconf gpgsm   grub-efi-amd64-signed libargon2-1 libbind9-160 libcap2-bin libcom-err2 libcryptsetup12 libdns-export1102 libdns1102 libext2fs2   libfstrm0 libgdbm-compat4 libgdbm6 libgpg-error-l10n libgraphite2-3 libharfbuzz0b libicu-le-hb0 libicu60 libisc-export169   libisc169 libisccc160 libisccfg160 libjson-c3 liblmdb0 liblwres160 libncurses6 libncursesw6 libnss-systemd libpam-cap libperl5.26   libprocps7 libprotobuf-c1 libpython2-stdlib libpython3.6-minimal libpython3.6-stdlib libtinfo6 libunistring2 libzstd1   linux-image-4.18.0-2-amd64 perl-modules-5.26 python2 python2-minimal python3-certifi python3-debconf python3-distutils
  python3-idna python3-lib2to3 python3.6 python3.6-minimal
The following packages will be upgraded:
  adduser apt apt-listchanges apt-utils base-files base-passwd bash bash-completion bind9-host bridge-utils bsdmainutils bsdutils   btrfs-progs busybox bzip2 ca-certificates console-setup console-setup-linux coreutils cpio cron dash dbus debconf debconf-i18n   debian-archive-keyring debianutils dh-python dictionaries-common diffutils discover distro-info-data dmidecode dmsetup dpkg   e2fslibs e2fsprogs efibootmgr emacsen-common file findutils gcc-6-base geoip-database gettext-base gnupg gnupg-agent gpgv grep   groff-base grub-common grub-efi-amd64 grub-efi-amd64-bin grub2-common gzip hdparm hostname iamerican ibritish ienglish-common   ifupdown init init-system-helpers initramfs-tools initramfs-tools-core installation-report iproute2 iptables iputils-ping   irqbalance isc-dhcp-client isc-dhcp-common iso-codes ispell kbd keyboard-configuration klibc-utils kmod krb5-locales laptop-detect   less libapparmor1 libapt-inst2.0 libapt-pkg5.0 libassuan0 libaudit-common libaudit1 libblkid1 libbsd0 libbz2-1.0 libc-bin   libc-l10n libc6 libcap-ng0 libcap2 libclass-isa-perl libcomerr2 libcurl3-gnutls libdb5.3 libdbus-1-3 libdebconfclient0   libdevmapper1.02.1 libdiscover2 libedit2 libefiboot1 libefivar1 libelf1 libestr0 libexpat1 libfastjson4 libfdisk1 libffi6   libfreetype6 libfuse2 libgcc1 libgcrypt20 libgeoip1 libglib2.0-0 libglib2.0-data libgmime-2.6-0 libgmp10 libgnutls-openssl27   libgnutls30 libgpg-error0 libgpgme11 libgpm2 libgssapi-krb5-2 libhogweed4 libidn11 libidn2-0 libip4tc0 libip6tc0 libiptc0   libk5crypto3 libkeyutils1 libklibc libkmod2 libkrb5-3 libkrb5support0 libldap-2.4-2 libldap-common liblocale-gettext-perl   liblockfile-bin liblogging-stdlog0 liblognorm5 liblz4-1 liblzma5 liblzo2-2 libmagic-mgc libmagic1 libmount1 libmpdec2 libncurses5   libncursesw5 libnetfilter-conntrack3 libnettle6 libnewt0.52 libnfnetlink0 libnghttp2-14 libnpth0 libnuma1 libp11-kit0   libpam-modules libpam-modules-bin libpam-runtime libpam-systemd libpam0g libpcre3 libpipeline1 libpng16-16 libpopt0 libpsl5   libpython-stdlib libpython2.7-minimal libpython2.7-stdlib libpython3-stdlib libreadline7 librtmp1 libsasl2-2 libsasl2-modules   libsasl2-modules-db libseccomp2 libselinux1 libsemanage-common libsemanage1 libsepol1 libslang2 libsmartcols1 libsqlite3-0 libss2   libssh2-1 libssl1.0.2 libssl1.1 libstdc++6 libsystemd0 libtalloc2 libtasn1-6 libtext-charwidth-perl libtext-iconv-perl libtinfo5   libtokyocabinet9 libudev1 libusb-0.1-4 libusb-1.0-0 libuuid1 libwrap0 libx11-6 libx11-data libxapian30 libxau6 libxcb1 libxml2   libxtables12 linux-image-amd64 locales login logrotate lsb-base lsb-release man-db manpages mime-support mount multiarch-support   mutt nano ncurses-base ncurses-bin ncurses-term netcat-traditional openssh-client openssh-server openssh-sftp-server openssl   os-prober passwd perl perl-base pinentry-curses popularity-contest powermgmt-base procps python python-apt-common python-minimal   python2.7 python2.7-minimal python3 python3-apt python3-chardet python3-debian python3-debianbts python3-httplib2 python3-minimal   python3-pkg-resources python3-pycurl python3-pysimplesoap python3-reportbug python3-requests python3-six python3-urllib3   readline-common rename reportbug rsyslog sed sensible-utils shared-mime-info systemd systemd-sysv sysvinit-utils tar task-english   task-ssh-server tasksel tasksel-data tcpd tzdata ucf udev util-linux util-linux-locales vim vim-common vim-runtime vim-tiny   wamerican wget whiptail xauth xdg-user-dirs xkb-data xml-core xxd xz-utils zlib1g
295 upgraded, 61 newly installed, 0 to remove and 0 not upgraded.
Need to get 182 MB of archives.
After this operation, 417 MB of additional disk space will be used.
Do you want to continue? [Y/n] Abort.

The upgrade is aborted without I have keyed anything !!!

What am I missing ?