Manually upgrade Debian from Buster to Bullseye Intro This simple tutorial displays how to upgrade your stable Debian OS to testing. The procedure displayed here is based on an upgrade from Debian Buster to Debian Bullseye, which is an upgrade from stable to testing at the time of writing. Despite that, this tutorial most likely can be used in the future just as well, as the only things that should change are the code names for the at the time current stable and testing distributions. Step By Step 1. Get the current OS information for reference head -1 /etc/os-release This should have the following output: PRETTY_NAME="Debian GNU/Linux 10 (buster)" 2. Find the right repositories 1. Visit https://www.debian.org/mirror/list 2. CTRL+F your country or area. 3. Pick an appropriate mirror. Almost all mirrors should be fine, if you are on a generic computer. If you are using an embedded device or something else special, be careful that you select a mirror that supports your requested architecture. 3. Upgrade the repository list Open up your /etc/apt/sources.list : sudo -sapt edit-sources Then comment out the existing entries by prepending each non-empty line with a pound key: #deb http://deb.debian.org/debian buster main#deb http://deb.debian.org/debian buster-updates main #deb http://security.debian.org/debian-security/ buster/updates main #deb http://ftp.debian.org/debian buster-backports main You can remove the pound key later, if you made a mistake and want to retrieve to the initial starting point. Now add the new URLs, mainly replacing buster with bullseye in this example: deb http://deb.debian.org/debian bullseye main contrib non-freedeb http://deb.debian.org/debian bullseye-updates main contrib non-freedeb http://security.debian.org/debian-security bullseye-security main deb http://ftp.debian.org/debian bullseye-backports main contrib non-free Test if the sources.list configuration is correct: apt update If you don't see any errors, you upgraded the list correctly. 4. Perform a backup It is extremely important to never rely that an upgrade of any sorts will go fine. Therefore, issuing a Backup of the entire OS is strongly recommended, before proceeding. 5. Upgrade the system Now, only after you performed a full system backup, upgrade your system: apt update apt full-upgrade && \ echo FINE || \echo FAIL If everything went fine, proceed with the next step. 6. Check the reference made in step 1 Compare the output of the command from step 1 with its output now: head -1 /etc/os-release Should now result in: PRETTY_NAME="Debian GNU/Linux bullseye/sid" Troubleshooting 1. If you encounter an error that resembles the following output: apt full-upgrade Reading package lists... Done Building dependency tree Reading state information... Done Calculating upgrade... Error!Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstabledistribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: libc6-dev : Breaks: libgcc-8-dev (< 8.4.0-2~) but 8.3.0-6+rpi1 is to be installed E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages. Then you need to do the following to fix it: apt install gcc-8-base Then, try apt full-upgrade again. It will work now. 2. If you encounter an error that resembles the following output: Errors were encountered while processing: /tmp/apt-dpkg-install-bOwYmi/226-libjs- jquery_3.5.1+dfsg-4_all.deb E: Sub-process /usr/bin/dpkg returned an error code (1) .... .... .... .... perl: warning: Setting locale failed.perl: warning: Please check that your locale settings: LANGUAGE = (unset), LC_ALL = "en_GB.UTF-8", LC_TIME = "en_GB.UTF-8", LC_CTYPE = "en_GB.UTF-8", LANG = "en_US.UTF-8" are supported and installed on your system.perl: warning: Falling back to the standard locale ("C"). locale: Cannot set LC_ALL to default locale: No such file or directorySetting up apt (2.1.7) ... Installing new version of config file /etc/apt/apt.conf.d/01autoremove ...Installing new version of config file /etc/cron.daily/apt-compat ...apt-daily-upgrade.timer is a disabled or a static unit not running, not starting it.apt-daily.timer is a disabled or a static unit not running, not starting it. Setting up mime-support (3.64) ...Installing new version of config file /etc/mime.types ... Setting up libmpdec2:armhf (2.4.2-3) ...Setting up libpython3.8-stdlib:armhf (3.8.5-1) ... Setting up python3.8 (3.8.5-1) ... Setting up libpython3-stdlib:armhf (3.8.2-3) ... Setting up python3 (3.8.2-3) ... running python rtupdate hooks for python3.8...running python post-rtupdate hooks for python3.8... Setting up distro-info-data (0.44) ... Setting up lsb-release (11.1.0) ... Setting up libsigsegv2:armhf (2.12-2) ...(Reading database ... 107447 files and directories currently installed.) Preparing to unpack .../libjs-jquery_3.5.1+dfsg-4_all.deb ...dpkg-maintscript-helper: error: file '/usr/share/javascript/jquery' not owned by package 'libjs-jquery:all'dpkg-maintscript- helper: error: file '/usr/share/javascript/jquery/jquery.min.js' not owned by package 'libjs- jquery:all'dpkg-maintscript-helper: error: file '/usr/share/javascript/jquery/jquery.min.map' not owned by package 'libjs-jquery:all'dpkg-maintscript-helper: error: file '/usr/share/javascript/jquery/jquery.js' not owned by package 'libjs-jquery:all'dpkg- maintscript-helper: error: directory '/usr/share/javascript/jquery' contains files not owned by package libjs-jquery:all, cannot switch to symlinkdpkg: error processing archive /var/cache/apt/archives/libjs-jquery_3.5.1+dfsg-4_all.deb (--unpack): new libjs-jquery package pre-installation script subprocess returned error exit status 1Errors were encountered while processing: /var/cache/apt/archives/libjs-jquery_3.5.1+dfsg-4_all.deb E: Sub-process /usr/bin/dpkg returned an error code (1) Then you need to do the following to fix it: dpkg --configure -a 3. If you encounter an error that resembles the following output: Setting up zfsutils-linux (0.8.4-2) ...zfs-import-scan.service is a disabled or a static unit, not starting it.Job for zfs-import-cache.service failed because the control process exited with error code.See "systemctl status zfs-import-cache.service" and "journalctl -xe" for details. zfs-import-scan.service is a disabled or a static unit, not starting it.Job for zfs-import- cache.service failed because the control process exited with error code.See "systemctl status zfs-import-cache.service" and "journalctl -xe" for details.Job for zfs-mount.service failed because the control process exited with error code.See "systemctl status zfs-mount.service" and "journalctl -xe" for details. invoke-rc.d: initscript zfs-mount, action "start" failed.● zfs-mount.service - Mount ZFS filesystems Loaded: loaded (/lib/systemd/system/zfs-mount.service; enabled; vendor preset: enabled) Active: failed (Result: exit-code) since Sat 2020-08-01 22:02:15 CEST; 28ms ago Docs: man:zfs(8) Process: 23251 ExecStart=/sbin/zfs mount -a (code=exited, status=127) Main PID: 23251 (code=exited, status=127)dpkg: error processing package zfsutils-linux (-- configure): installed zfsutils-linux package post-installation script subprocess returned error exit status 1 Setting up udev (245.6-2) ...Job for systemd-udevd.service failed because the control process exited with error code.See "systemctl status systemd-udevd.service" and "journalctl -xe" for details. invoke-rc.d: initscript udev, action "restart" failed.● systemd-udevd.service - udev Kernel Device Manager Loaded: loaded (/lib/systemd/system/systemd-udevd.service; static; vendor preset: enabled) Active: activating (start) since Sat 2020-08-01 22:02:21 CEST; 24ms ago TriggeredBy: ● systemd-udevd-kernel.socket ● systemd-udevd-control.socket Docs: man:systemd- udevd.service(8) man:udev(7) Main PID: 23358 (systemd-udevd) Tasks: 1 Memory: 156.0K CGroup: /system.slice/systemd-udevd.service └─23358 [systemd-udevd] dpkg: error processing package udev (--configure): installed udev package post-installation script subprocess returned error exit status 1dpkg: dependency problems prevent configuration of udisks2: udisks2 depends on udev; however: Package udev is not configured yet. dpkg: error processing package udisks2 (--configure): dependency problems - leaving unconfigured Errors were encountered while processing: zfsutils-linux udev udisks2 E: Sub-process /usr/bin/dpkg returned an error code (1) .... .... .... .... dpkg --configure udev Setting up udev (245.6-2) ...Job for systemd-udevd.service failed because the control process exited with error code.See "systemctl status systemd-udevd.service" and "journalctl -xe" for details. invoke-rc.d: initscript udev, action "restart" failed.● systemd-udevd.service - udev Kernel Device Manager Loaded: loaded (/lib/systemd/system/systemd-udevd.service; static; vendor preset: enabled) Active: activating (start) since Sun 2020-08-02 00:47:34 CEST; 25ms ago TriggeredBy: ● systemd-udevd-kernel.socket ● systemd-udevd-control.socket Docs: man:systemd- udevd.service(8) man:udev(7) Main PID: 26603 (systemd-udevd) Tasks: 1 Memory: 236.0K CGroup: /system.slice/systemd-udevd.service └─26603 [systemd-udevd] dpkg: error processing package udev (--configure): installed udev package post-installation script subprocess returned error exit status 1 Errors were encountered while processing: udev .... .... .... .... systemctl status systemd-udevd.service● systemd-udevd.service - udev Kernel Device Manager Loaded: loaded (/lib/systemd/system/systemd-udevd.service; static; vendor preset: enabled) Active: failed (Result: exit-code) since Sun 2020-08-02 00:47:35 CEST; 1min 22s ago TriggeredBy: ● systemd-udevd-kernel.socket ● systemd-udevd-control.socket Docs: man:systemd- udevd.service(8) man:udev(7) Process: 26611 ExecStart=/lib/systemd/systemd-udevd (code=exited, status=127) Main PID: 26611 (code=exited, status=127) ...