[arch-general] pacman overwriting files (was Re: dcron 4.2)

[Aaron Griffin]

On Thu, Feb 11, 2010 at 11:26 AM, Dimitrios Apostolou <jimis at gmx.net> wrote:
> On Wed, 10 Feb 2010, Thomas Bächler wrote:
>>
>> Am 10.02.2010 21:30, schrieb Dimitrios Apostolou:
>>>
>>> Guys that thing bit me again: During the big libpng upgrade
>>> "initscripts" package got upgraded too and /etc/rc.{sysinit,shutdown}
>>> got overwritten without notifying me. Because of special changes I've
>>> made to mount /var as tmpfs, and because I forgot to put the files in
>>> the NoUpgrade line of pacman.conf, the system was unbootable and after
>>> fixing it pacman wants to download 500MB of packages again (ideas?). :-@
>>>
>>> Can't pacman just emit a big fat warning like: WARNING: /etc/rc.sysinit
>>> USER CHANGES OVERWRITTEN
>>>
>>> Since this case is extremely rare, the message would appear scarcely. I
>>> can't thing of anything negative for such a feature.
>>
>> This will definitely not happen. pacman will only notify you on files
>> that are marked as "backup" in the package and thus listed in pacman
>> -Qii! All other will be overwritten without a warning (pacman doesn't
>> know you modified them). rc.{sysinit,shutdown} are not supposed to be
>
> Thanks for the info, so it's not a matter of policy but I now see it's
> technically not feasible... I wish this was mentioned before. I now noticed
> that pacman stores the checksums of files in the %PACMAN% array inside
> "files" file. I somehow was under the impression that no checksums were
> needed, only the timestams inside the installation tarball.
>
>> modified by the user - if you still want to do that, the NoUpgrade
>> feature of pacman will do the job, but then you are completely on your
>> own (Arch gives you all freedom you want, as long as you know you and
>> only you are to blame for problems)!
>>
>> You should try to make your changes work inside Arch:
>> 1) If your changes are general enough to make it into the mainstream
>> initscripts as a feature (or an optional one), submit a feature request
>> with a patch against latest git.
>> 2) If your changes are for local usage only, try to integrate them with
>> the new initscripts hooks system. You can also request to add more hooks
>> to be added in initscripts, just open a feature request. The hooks
>> system is explained in the comments in /etc/rc.d/functions.
>>
>
> My patch is only 3 lines before any other initialisation has taken place,
> and copies /var from disk to tmpfs. I'm using it on my Eee 901 for over one
> year, but it's really custom and non-portable. I didn't know about the new
> hooks system, I think I like it. When I find some time to port my 3-lines
> patch to it, I'll post it here in case someone else needs it.

I'm sure, using the hooks system, you can add a very early hook that
just mounts /var on tmpfs. Problem solved :)