Comment 8 for bug 1981672

a downgrade is possible:

hostname:~# apt policy libmysqlclient21
libmysqlclient21:
  Installed: 8.0.29-0ubuntu0.22.04.3
  Candidate: 8.0.29-0ubuntu0.22.04.3
  Version table:
 *** 8.0.29-0ubuntu0.22.04.3 500 (phased 10%)
        500 http://ubuntu.ethz.ch/ubuntu jammy-updates/main amd64 Packages
        500 http://ubuntu.ethz.ch/ubuntu jammy-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
     8.0.29-0ubuntu0.22.04.2 500
        500 http://ubuntu.ethz.ch/ubuntu jammy-security/main amd64 Packages
     8.0.28-0ubuntu4 500
        500 http://ubuntu.ethz.ch/ubuntu jammy/main amd64 Packages
hostname:~# apt install libmysqlclient21=8.0.29-0ubuntu0.22.04.2
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libaom-dev libarmadillo-dev libarpack2-dev libavformat-dev libblosc-dev libcharls-dev libdav1d-dev
  libde265-dev libdouble-conversion-dev libfreexl-dev libfyba-dev libgeos-dev libgeotiff-dev libgl2ps-dev
  libglew-dev libheif-dev libjson-c-dev libjsoncpp-dev libkml-dev libkmlconvenience1 libkmlregionator1
  libkmlxsd1 liblapack-dev libnetcdf-c++4 libnetcdf-cxx-legacy-dev libogdi-dev libopenjp2-7-dev libopenni2-0
  libopenni2-dev libpcl-apps1.12 libpcl-common1.12 libpcl-features1.12 libpcl-filters1.12 libpcl-io1.12
  libpcl-kdtree1.12 libpcl-keypoints1.12 libpcl-ml1.12 libpcl-octree1.12 libpcl-outofcore1.12 libpcl-people1.12
  libpcl-recognition1.12 libpcl-registration1.12 libpcl-sample-consensus1.12 libpcl-search1.12
  libpcl-segmentation1.12 libpcl-stereo1.12 libpcl-surface1.12 libpcl-tracking1.12 libpcl-visualization1.12
  libpoppler-dev libpoppler-private-dev libproj-dev librttopo-dev libspatialite-dev libsuperlu-dev
  libswscale-dev libtheora-dev liburiparser-dev libusb-1.0-0-dev libutfcpp-dev libvtk9-java libvtk9.1-qt
  libx265-dev libzstd-dev python3-vtk9 qttools5-private-dev tcl-dev tcl8.6-dev tk-dev tk8.6-dev vtk9
Use 'apt autoremove' to remove them.
The following packages will be REMOVED:
  default-libmysqlclient-dev libgdal-dev libmysqlclient-dev libpcl-dev libvtk9-dev libvtk9-qt-dev
The following packages will be DOWNGRADED:
  libmysqlclient21
0 upgraded, 0 newly installed, 1 downgraded, 6 to remove and 0 not upgraded.
Need to get 1,273 kB of archives.
After this operation, 102 MB disk space will be freed.
Do you want to continue? [Y/n]

hostname:~# apt install libmysqlclient21
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libaom-dev libarmadillo-dev libarpack2-dev libavformat-dev libblosc-dev libcharls-dev libdav1d-dev
  libde265-dev libdouble-conversion-dev libfreexl-dev libfyba-dev libgeos-dev libgeotiff-dev libgl2ps-dev
  libglew-dev libheif-dev libjson-c-dev libjsoncpp-dev libkml-dev libkmlconvenience1 libkmlregionator1
  libkmlxsd1 liblapack-dev libnetcdf-c++4 libnetcdf-cxx-legacy-dev libogdi-dev libopenjp2-7-dev libopenni2-0
  libopenni2-dev libpcl-apps1.12 libpcl-common1.12 libpcl-features1.12 libpcl-filters1.12 libpcl-io1.12
  libpcl-kdtree1.12 libpcl-keypoints1.12 libpcl-ml1.12 libpcl-octree1.12 libpcl-outofcore1.12 libpcl-people1.12
  libpcl-recognition1.12 libpcl-registration1.12 libpcl-sample-consensus1.12 libpcl-search1.12
  libpcl-segmentation1.12 libpcl-stereo1.12 libpcl-surface1.12 libpcl-tracking1.12 libpcl-visualization1.12
  libpoppler-dev libpoppler-private-dev libproj-dev librttopo-dev libspatialite-dev libsuperlu-dev
  libswscale-dev libtheora-dev liburiparser-dev libusb-1.0-0-dev libutfcpp-dev libvtk9-java libvtk9.1-qt
  libx265-dev libzstd-dev python3-vtk9 qttools5-private-dev tcl-dev tcl8.6-dev tk-dev tk8.6-dev vtk9
Use 'apt autoremove' to remove them.
The following packages will be upgraded:
  libmysqlclient21
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 1,273 kB of archives.
After this operation, 0 B of additional disk space will be used.
Get:1 http://ubuntu.ethz.ch/ubuntu jammy-updates/main amd64 libmysqlclient21 amd64 8.0.29-0ubuntu0.22.04.3 [1,273 kB]
Fetched 1,273 kB in 0s (16.9 MB/s)
(Reading database ... 750292 files and directories currently installed.)
Preparing to unpack .../libmysqlclient21_8.0.29-0ubuntu0.22.04.3_amd64.deb ...
Unpacking libmysqlclient21:amd64 (8.0.29-0ubuntu0.22.04.3) over (8.0.29-0ubuntu0.22.04.2) ...
Setting up libmysqlclient21:amd64 (8.0.29-0ubuntu0.22.04.3) ...
Processing triggers for libc-bin (2.35-0ubuntu3.1) ...
/sbin/ldconfig.real: /lib/libXp.so.6 is not a symbolic link

/sbin/ldconfig.real: /lib/libgfortran.so.3 is not a symbolic link

Scanning processes...
Scanning candidates...
Scanning processor microcode...
Scanning linux images...

The processor microcode seems to be up-to-date.

Restarting services...
Service restarts being deferred:
 systemctl restart accounts-daemon.service
 systemctl restart autofs.service
 systemctl restart canna.service
 systemctl restart colord.service
 systemctl restart cron.service
 /etc/needrestart/restart.d/dbus.service
 systemctl restart fail2ban.service
 systemctl restart <email address hidden>
 systemctl restart inventory.service
 systemctl restart irqbalance.service
 systemctl restart lightdm.service
 systemctl restart multipathd.service
 systemctl restart nfs-idmapd.service
 systemctl restart nfs-mountd.service
 systemctl restart nfsdcld.service
 systemctl restart nohang.service
 systemctl restart polkit.service
 systemctl restart postfix@-.service
 systemctl restart rasdaemon.service
 systemctl restart rpc-statd.service
 systemctl restart rpcbind.service
 systemctl restart rsyslog.service
 systemctl restart ssh.service
 systemctl restart sssd.service
 systemctl restart systemd-journald.service
 systemctl restart systemd-logind.service
 systemctl restart systemd-networkd.service
 systemctl restart systemd-resolved.service
 systemctl restart systemd-timesyncd.service
 systemctl restart systemd-udevd.service
 systemctl restart thermald.service
 systemctl restart udisks2.service
 systemctl restart user@120.service
 systemctl restart uuidd.service
 systemctl restart xrdp-sesman.service
 systemctl restart xrdp.service

No containers need to be restarted.

No user sessions are running outdated binaries.

No VM guests are running outdated hypervisor (qemu) binaries on this host.

hostname:~# apt dist-upgrade
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
  libaom-dev libarmadillo-dev libarpack2-dev libavformat-dev libblosc-dev libcharls-dev libdav1d-dev
  libde265-dev libdouble-conversion-dev libfreexl-dev libfyba-dev libgeos-dev libgeotiff-dev libgl2ps-dev
  libglew-dev libheif-dev libjson-c-dev libjsoncpp-dev libkml-dev libkmlconvenience1 libkmlregionator1
  libkmlxsd1 liblapack-dev libnetcdf-c++4 libnetcdf-cxx-legacy-dev libogdi-dev libopenjp2-7-dev libopenni2-0
  libopenni2-dev libpcl-apps1.12 libpcl-common1.12 libpcl-features1.12 libpcl-filters1.12 libpcl-io1.12
  libpcl-kdtree1.12 libpcl-keypoints1.12 libpcl-ml1.12 libpcl-octree1.12 libpcl-outofcore1.12 libpcl-people1.12
  libpcl-recognition1.12 libpcl-registration1.12 libpcl-sample-consensus1.12 libpcl-search1.12
  libpcl-segmentation1.12 libpcl-stereo1.12 libpcl-surface1.12 libpcl-tracking1.12 libpcl-visualization1.12
  libpoppler-dev libpoppler-private-dev libproj-dev librttopo-dev libspatialite-dev libsuperlu-dev
  libswscale-dev libtheora-dev liburiparser-dev libusb-1.0-0-dev libutfcpp-dev libvtk9-java libvtk9.1-qt
  libx265-dev libzstd-dev python3-vtk9 qttools5-private-dev tcl-dev tcl8.6-dev tk-dev tk8.6-dev vtk9
Use 'apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
hostname:~# apt-get dist-upgrade
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
  libaom-dev libarmadillo-dev libarpack2-dev libavformat-dev libblosc-dev libcharls-dev libdav1d-dev
  libde265-dev libdouble-conversion-dev libfreexl-dev libfyba-dev libgeos-dev libgeotiff-dev libgl2ps-dev
  libglew-dev libheif-dev libjson-c-dev libjsoncpp-dev libkml-dev libkmlconvenience1 libkmlregionator1
  libkmlxsd1 liblapack-dev libnetcdf-c++4 libnetcdf-cxx-legacy-dev libogdi-dev libopenjp2-7-dev libopenni2-0
  libopenni2-dev libpcl-apps1.12 libpcl-common1.12 libpcl-features1.12 libpcl-filters1.12 libpcl-io1.12
  libpcl-kdtree1.12 libpcl-keypoints1.12 libpcl-ml1.12 libpcl-octree1.12 libpcl-outofcore1.12 libpcl-people1.12
  libpcl-recognition1.12 libpcl-registration1.12 libpcl-sample-consensus1.12 libpcl-search1.12
  libpcl-segmentation1.12 libpcl-stereo1.12 libpcl-surface1.12 libpcl-tracking1.12 libpcl-visualization1.12
  libpoppler-dev libpoppler-private-dev libproj-dev librttopo-dev libspatialite-dev libsuperlu-dev
  libswscale-dev libtheora-dev liburiparser-dev libusb-1.0-0-dev libutfcpp-dev libvtk9-java libvtk9.1-qt
  libx265-dev libzstd-dev python3-vtk9 qttools5-private-dev tcl-dev tcl8.6-dev tk-dev tk8.6-dev vtk9
Use 'apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

and will get the phased update anymore after the downgrade.