o1bigtenor via Dng wrote:
> On Wed, Apr 20, 2022 at 6:37 AM Antony Stone
> <Antony.Stone@???> wrote:
>> On Wednesday 20 April 2022 at 13:17:48, o1bigtenor via Dng wrote:
>>
>>> Greetings
>>>
>>> In the process of upgrading my system I now am stuck at a point where
>>> I don't know how to resolve the conundrum.
>>>
>>> /bin/sh: 1: /usr/bin/apt-listchanges: not found
>>> E: Sub-process /usr/bin/apt-listchanges --apt || test $? -lt 10
>>> returned an error code (1)
>>> E: Failure running script /usr/bin/apt-listchanges --apt || test $? -lt 10
>>>
>>> when I go to look at the files and folders in /usr/bin/ I can find
>>> this apt-listchanges but somehow the apt 'system' isn't seeing it or
>>> is seeing it poorly.
>>>
>>> When I try apt --fix-broken install I the same message.
>>>
>>> How do I resolve this - - - - -please?
>> I found myself in exactly this situation recently.
>>
>> I had a machine running Beowulf with all mounted file systems as LVM logical
>> volumes. I created a duplicate LV of the root file system and rebooted from
>> it, then performed an upgrade to Chimaera.
>>
>> I wasn't happy (for reasons that don't matter here) with the result, so I
>> simply re-booted back into the untouched Beowulf root FS.
>>
>> Unfortunately I had neglected to consider the consequences of my having
>> created a separate /var partition in the first place, which got used by the
>> Chimaera upgrade, and was then thoroughly corrupted as far as Beowulf was
>> concered (mainly due to /var/dpkg, I'm sure).
>>
>> It turned out that the "/usr/bin/apt-listchanges: not found" message is highly
>> misleading, and means that the script could not find the Python interpreter it
>> expected to, not that the script itself could not be found.
>>
>> So, I think if you look at the first line of that script on your system, it
>> will point to something like /usr/bin/python3, which is probably a symlink to
>> something else in /usr/bin, which does not exist.
>>
>> I hope this should at least give you some pointers as to what it is you need
>> to fix - get the correct version of Python3 installed.
>>
> I had just previously deleted the folder python3.9 but python3.10 was
> right beside so thought deleting the previous would make more room (which I
> desperately need!!).
>
> When looking at the first lines in apt-listchanges - - - well I'm no programmer
> but the code looks more like Perl to me with the use of the :: directives but
> I dunno much about programming so that could be right out to lunch!!!
>
> Not seeing anything like what you're describing - - - sorry.
>
> When the tools to fix the broken tools don't work - - - - what are the options?
> Is there only a re-install?
> (That would be scary - - - - this is a complicated system and I've got piles
> of software installed!! - - - last time I did this things were quite hairy for
> quite a while!!!! Not fun at all!)
>
> Thank you for the information - - - good to know that the error message
> really doesn't connect with the real world - - - - I wasn't even able
> to find any
> references on the web - - - - ZERO - - - which - - I thought was sorta unusual!
>
> Regards
>

I'm running on beowulf... your results may be slightly different
Let's not worry about the code inside apt-listchanges, at this point. 
Just check the script interpreter for now

~$ head -n 1 /usr/bin/apt-listchanges
should give a result similar to this:
#!/usr/bin/python3

then, taking the result given,
~$ file /usr/bin/python3
should give another result similar to this:
/usr/bin/python3: symbolic link to python3.7

then, check the target of that symbolic link:
~$ file /usr/bin/python3.7
the result is: ELF 64-bit LSB executable, .....

if any of these fails (for example, python3 may be a broken symbolic
link to python3.7), then reinstalling python3 should fix the issue,
hopefully.
on the other hand, if this all checks out good, the problem may lie
elsewhere.