Re: Stretch stable and jessie testing - repositories listed
thank you very much
David Wright:
> On Sat 11 Feb 2017 at 12:35:00 (+0000), GiaThnYgeia wrote:
>> Jimmy Johnson:
>>> On 02/10/2017 05:49 PM, David Wright wrote:
>>>> On Fri 10 Feb 2017 at 16:00:13 (-0800), Jimmy Johnson wrote:
>>>>> Hello,
>>>>> Take a look at Synaptic Menu you can select a package and then go to
>>>>> Package > Force Version, you can only force one package at a time
>>>>> but, yes you can downgrade. I can down grade a couple hundred
>>>>> packages without much problem, depends on the user.
>>>>
>>>> Oh, that's heartening! Does Synaptic use a different method
>>>> from dpkg? The man page for the latter says (and the warnings
>>>> look very pretty in red):
>>>> Warning: At present dpkg does not do any dependency checking on
>>>> downgrades and therefore will not warn you if the downgrade
>>>> breaks the dependency of some other package. This can have seri‐
>>>> ous side effects, downgrading essential system components can
>>>> even make your whole system unusable. Use with care.
>>>> Cheers,
>>>> David.
>>>
>>> Hi David, Synaptic will not let you install a broken package. If you
>>> are running sid/testing sometimes a package version will become obsolete
>>> and need a change or a video driver version is not working and needs a
>>> change, etc. If you're running in a GUI Synaptic is handy to have
>>> installed. And yes, it's using "dpkg".
>>
>> One thing I have not been able to find in synaptic or elsewhere is a way
>> to keep track of what has been installed and when. If you know where
>> such a log habitates or can be created let me/us know.
>
> I use aptitude rather than synaptic so you'll have to compensate for
> that in what follows. There are three logs that I use.
>
> The first is /var/log/aptitude.log which is rotated for only six
> months. (I don't think I've changed any log rotation parameters.)
> This only shows what you told aptitude itself to do, and only your
> intentions, not the results (which might have been unsuccessful).
> It also doesn't bother about versions, only package names.
>
> The second was mentioned and is /var/log/apt/history.log which is
> rotated for twelve months. This includes changes made with both
> aptitude and apt-get, and it includes the previous and new version
> numbers. That makes it messy to parse as you have to deal with
> two levels of commas: ... pkga (ver1, ver2), pkgb (ver3, ver4), ...
>
> The third is /var/log/apt/term.log (also twelve months) which logs
> all the results of apt's work, but lacks any of your input. So you
> need to look at the other logs to find out why apt did what it did.
> It's very long-winded because it even includes the "progress bars".
>
>> I understand it all relates to what depends on what and who is breaking
>> whom. If it is a package that depends on other "stuff" but nothing
>> depends on it you can install something from debian1 in its beta version
>> and all else is fine. But if you go one version back of one little
>> thing that 100 things depend on, you may get 90 things not working.
>> This is my simplistic understanding. Out of my panic experimentation I
>> have run into situations that it becomes a great puzzle of why the
>> system is still working. Like creating a mess and breaking the system
>> then reinstalling an earlier version of the distribution ON TOP of the
>> mesh, same root and user names and passwords,
>> then try to locate all the things that had been installed and upgraded
>> that are not on the dpkg list and if not recovered they will remain
>> unupdated. And it works! Like magic! I think all synaptic does is
>> simplifying and remembering all the correct syntax of dpkg commands and
>> executing them for you.
>
> Well, I'd be interested to see the term.log from a session where
> someone downgrades "a couple hundred packages without much problem"
> as reported above. According to your experience, their statement of
> "depends on the user" is untrue. Synaptic just sorts it all out for
> you, though that's surprising in view of your last sentence.
>
> I have little experience of downgrading, but have read plenty of
> postings here about how difficult it can be. I would want a solid
> backup system in place at the time, particularly if I were paying
> bills with the work. In the past I always depended on having duplicate
> systems and some bash scripts to get from the debian-installer to a
> working system in short order.
>
> Cheers,
> David.
>
--
"The most violent element in society is ignorance" rEG
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