Buster to Bullseye upgrade problem

["Gareth Evans" <donotspam@fastmail.fm>]

Hello,

I upgraded from Buster stable to Bullseye stable last night, with apparent success eventually, but it went less than smoothly and I would be grateful for any advice as to why that may have been.

I followed the preparation advice at

https://www.debian.org/releases/bullseye/amd64/release-notes/ch-upgrading.en.html

and it seemed to me that there were no non-Debian packages in apt-forktracer output, although I'm afraid I didn't save the list.

The upgrade process stopped abruptly a couple of times, once without any indication as to why.

$ cat /etc/apt/sources.list
deb http://deb.debian.org/debian/ bullseye main contrib non-free
deb http://deb.debian.org/debian/ bullseye-updates main contrib non-free
#deb http://deb.debian.org/debian bullseye-proposed-updates main contrib non-free
deb http://deb.debian.org/debian-security/ bullseye-security main contrib non-free
deb http://deb.debian.org/debian/ bullseye-backports main contrib non-free


>From script output:

# apt full-upgrade
[...]
Errors were encountered while processing:
 /tmp/apt-dpkg-install-2vllSE/09-gir1.2-gst-plugins-bad-1.0_1.18.4-3_amd64.deb
<upgrade stopped, etckeeper output snipped>
E: Sub-process /usr/bin/dpkg returned an error code (1)

# apt install --fix-broken
[...]
Setting up zfs-initramfs (2.0.3-9) ...
Processing triggers for initramfs-tools (0.133+deb10u1) ...
update-initramfs: Generating /boot/initrd.img-4.19.0-17-amd64

# apt full-upgrade
[...]
Processing triggers for libapache2-mod-php7.4 (7.4.21-1+deb11u1) ...
<upgrade stopped, etckeeper output snipped>
W: APT had planned for dpkg to do more than it reported back (8974 vs 9007).
   Affected packages: texlive-fonts-recommended:amd64 texlive-lang-greek:amd64 texlive-latex-base:amd64 texlive-latex-extra:amd64 texlive-latex-recommended:amd64 texlive-pictures:amd64 texlive-plain-generic:amd64 texlive-science:amd64

# apt full-upgrade
[...]

Apparent success...

$ apt policy *gir*bad*
gir1.2-gst-plugins-bad-1.0:
  Installed: 1.18.4-3
  Candidate: 1.18.4-3
  Version table:
 *** 1.18.4-3 500
        500 http://deb.debian.org/debian bullseye/main amd64 Packages
        100 /var/lib/dpkg/status

$ cat /etc/debian_version
11.0

$ uname -a
Linux <hostname> 5.10.0-8-amd64 #1 SMP Debian 5.10.46-4 (2021-08-03) x86_64 GNU/Linux

Reboots without issue. 

Is there any way to verify an upgrade completed properly?  Would there be obvious errors on exit if it didn't?

Thanks,
Gareth