After system upgrade from ubuntu 20.04 LTS to ubuntu 22.04.1 LTS firefox error when doing `sudo apt --fix-broken install` - firefox

Question

After upgrade from ubuntu 20.04 LTS to 22.04.1 LTS, I got a very persistent error:
(Reading database ... 350976 files and directories currently installed.)
Preparing to unpack .../firefox_1%3a1snap1-0ubuntu2_amd64.deb ...
=> Installing the firefox snap
==> Checking connectivity with the snap store
==> Installing the firefox snap
error: cannot perform the following tasks:
- Run hook connect-plug-host-hunspell of snap "firefox" (run hook "connect-plug-
host-hunspell": cannot perform operation: mount --rbind /var/log /tmp/snap.rootf
s_hE2Zj1//var/log: Permission denied)
dpkg: error processing archive /var/cache/apt/archives/firefox_1%3a1snap1-0ubunt
u2_amd64.deb (--unpack):
new firefox package pre-installation script subprocess returned error exit stat
us 1
Please restart all running instances of firefox, or you will experience problems
.
Errors were encountered while processing:
/var/cache/apt/archives/firefox_1%3a1snap1-0ubuntu2_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
This
- Run hook connect-plug-host-hunspell of snap "firefox" (run hook "connect-plug-
host-hunspell": cannot perform operation: mount --rbind /var/log /tmp/snap.rootf
s_hE2Zj1//var/log: Permission denied)
was very persistent and was hindering any apt-involved installations.
Thus, no apt install nor apt upgrade was working.

Answer 1

After long search and trying around,
where I did:
sudo apt --fix-broken install
sudo rm /var/lib/dpkg/lock
sudo rm /var/lib/dpkg/lock-frontend
sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock
sudo dpkg --configure -a
And then, cave(!) this removes firefox from your installed package list
and thus after this command you cannot use firefox any more on your computer
until you install it - so I did that - but I had a second computer
where I could google around while I had no firefox on that machine.
I couldn't install chromium browser or other browsers, because apt was not working! So run this command only when you have a second computer or at least your mobile to surf for instructions!
sudo dpkg --force depends -P firefox
I found a hint in
https://forums.mozillazine.org/viewtopic.php?f=38&t=3097766
My solution was:
# Add Mozilla Team PPA
sudo add-apt-repository ppa:mozillateam/ppa
# Set PPA priority
sudo gedit /etc/apt/preferences.d/mozillateamppa
# The command creates and opens empty config file in Gedit text editor.
# When it opens, add the lines below and save it:
Package: firefox*
Pin: release o=LP-PPA-mozillateam
Pin-Priority: 501
save and close that file.
after that, I could do finally:
sudo apt --fix-broken install
# and then:
sudo apt update && sudo apt upgrade
and then, all apt or snap commands were working again flawlessly.
note:
Now, I encounter
sudo apt install chromium-browser
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following NEW packages will be installed:
chromium-browser
0 upgraded, 1 newly installed, 0 to remove and 4 not upgraded.
Need to get 0 B/48,4 kB of archives.
After this operation, 164 kB of additional disk space will be used.
Preconfiguring packages ...
(Reading database ... 313313 files and directories currently installed.)
Preparing to unpack .../chromium-browser_1%3a85.0.4183.83-0ubuntu2_amd64.deb ...
=> Installing the chromium snap
==> Checking connectivity with the snap store
==> Installing the chromium snap
error: cannot perform the following tasks:
- Run configure hook of "chromium" snap if present (run hook "configure": cannot perform operation: mount --rbind /var/log /
tmp/snap.rootfs_Gg42mE//var/log: Permission denied)
dpkg: error processing archive /var/cache/apt/archives/chromium-browser_1%3a85.0.4183.83-0ubuntu2_amd64.deb (--unpack):
new chromium-browser package pre-installation script subprocess returned error exit status 1
Errors were encountered while processing:
/var/cache/apt/archives/chromium-browser_1%3a85.0.4183.83-0ubuntu2_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
I tried:
sudo add-apt-repository ppa:xtradeb/apps
sudo gedit /etc/apt/preferences.d/xtradebppa
# content:
Package: chromium*
Pin: release o=LP-PPA-xtradeb
Pin-Priority: 501
But this didn't help.

Answer 2

Finally, I found out the solution!
In former days, when my / containing system partition was too full, I sym-linked /var/log. I linked it to somehwere in my home folder. But then, I moved snap back.
- Run hook connect-plug-host-hunspell of snap "firefox" (run hook "connect-plug-
host-hunspell": cannot perform operation: mount --rbind /var/log /tmp/snap.rootf
s_hE2Zj1//var/log: Permission denied)
The permission was denied, because it tried to mount to a symlink.
All I had to do was:
sudo rm /var/log
sudo mkdir -p /var/log
Now, it is not a symlink any more. So it can actually mount to it.