dpkg: error processing package unattended-upgrades during upgrade to 20.04

"the installation halted when trying to show the code side by side for package unattended-upgrades, the new terminal window became unresponsive and froze."

During package installation or upgrade in some cases you get a dialogue window asking certain additional questions (e.g. "do you want to keep your existing config file, or replace it with the one provided by the new version of the package").

In these dialogues the mouse does not work, and you can navigate only with the keyboard (up, down, left, right, tab, space to select, enter to confirm).

I assume that you did not know how to work with that kind of terminal windows and did not see any option but aborting the process.

You write that apt update && apt upgrade is working without any problems, so I assume that nothing is broken.

And, by the way, it is recommended that all users with well-functioning Ubuntu 18.04 installations should wait with the upgrade to 20.04
From https://lists.ubuntu.com/archives/ubuntu-announce/2020-April/000256.html
Users of Ubuntu 19.10 will be offered an automatic upgrade to 20.04 LTS via Update Manager shortly. Users of 18.04 LTS will be offered the automatic upgrade when 20.04.1 LTS is released, which is scheduled for July 23rd.

I'm happy that i asked before reporting the issue since it seems i lacked proper wording of the issue.

"During my upgrade from Ubuntu 18.04 to 20.04 by software updater or update manager the installation halted when trying to show the code side by side for package unattended-upgrades, the new terminal window became unresponsive and froze"

To reiterate for clarity.
When update manger tried to start a new process for a new terminal window that window immediately became unresponsive and produced neither text nor a command prompt for user input.
The system then reported that the window was unresponsive and i chose to close that window since it was halting the installation.
This then resulted in me not having a choice at this point to select whether i would choose to keep my existing config file, or replace it with the one provided by the new version of the package.
Hence my question for the report

As you stated the system is working properly, i was only curious if i should make an official bug report since the terminal became unresponsive when trying to view the difference.

I don't see how the answer resolves the original question ?

You have aborted the terminal windows with the side-by-side display of the config files.
These kind of windows do not show a mouse cursor or react on the mouse, and there is no command prompt to enter something. Just navigate in that window with the arrow keys, space bar, tab and enter.
You will see that some parts of the text change the color to indicate that they are (un-)selected.

What is your original question which is unanswered?
Whether you should report a bug?
In my opinion you shouldn't, unless you can show how to make that problem re-appear.

"When update manger tried to start a new process for a new terminal window that window immediately became unresponsive and produced neither text nor a command prompt for user input."
What i tried to explain here was that there never was any code side by side. That the option of selecting code side by side, by using the keyboard resulted in a unresponsive terminal window, not from lack of familiarity.

I am familiar with the window showing code side by side, that is why i selected that option.
From the moment i selected view config side by side, it spawned a new terminal window and that new terminal window was unresponsive.
So it never showed any code, any input from the keyboard or otherwise just resulted in a system message reporting that terminal window was unresponsive.

The system message reported the terminal window as unresponsive" Wait or Force Quit. "

So i first waited seeing this might take some time or there might be quite a lot in the config, but since this led to no result and when i attempted to interact with the window again by keyboard or otherwise.
I was yet again prompted with an option to either wait for the program to become responsive or kill it.
This is when i aborted it yes, since a blank window with no config files is not of any use.
My question related to the issue was, whether if i should report this as a bug, yes.

Seeing as you don't see a reason for me to report this as a bug i will take your word for it.