Raspberry Pi OS を buster から bullseye に dist-upgrade

$ sudo mount -o remount,rw /boot (1)
$ sudo apt update (2)
$ sudo apt upgrade (3)
$ sudo reboot (4)

$ script -a ~/buster2bullseye_$(date +%F-%T).log

$ dpkg --audit (1)
$ dpkg --get-selections | grep 'hold

$ sudo apt edit-sources
$ cat /etc/apt/sources.list
deb http://raspbian.raspberrypi.org/raspbian/ bullseye main contrib non-free rpi
deb-src http://raspbian.raspberrypi.org/raspbian/ bullseye main contrib non-free rpi

$ sudo apt update

$ sudo apt -o APT::Get::Trivial-Only=true full-upgrade

$ sudo mount -o remount,rw /boot

$ sudo apt install openssh-server

$ sudo apt upgrade --without-new-pkgs

$ sudo apt full-upgrade

$ sudo 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 unstable
distribution 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.

$ sudo apt install gcc-8-base libc6-dev
$ sudo apt full-upgrade

[all]
#dtoverlay=vc4-fkms-v3d (1)
dtoverlay=vc4-kms-v3d (2)