[Aptitude-devel] Bug#809347: apt-get upgrade gets much farther than aptitude thanks to APT::Get::Fix-Missing

[Manuel A. Fernandez Montecelo]

tags 825898 + wontfix
close 825898
stop


(This is somehow a duplicate of #809347 ... copying it here).


Hi,

2016-05-31 08:36 積丹尼 Dan Jacobson:
>Package: aptitude
>Version: 0.8.1-1
>Severity: wishlist
>
>apt-get upgrade, when using
>APT::Get::Fix-Missing true;
>gets a lot more installed that
>aptitude safe-upgrade

For reference for other people reading or future revision of this
bug... as David says in #825897, having this option permanently enabled
is probably not a good idea.


>aptitude usually gives up when any more than a few of the downloads
>fail, (e.g., when one is offline.)
>
>164 packages upgraded, 8 newly installed, 4 to remove and 14 not upgraded.
>Need to get 11.4 MB/299 MB of archives. After unpacking 27.3 MB will be freed.
>Do you want to continue? [Y/n/?]
>Err http://free.nchc.org.tw/debian unstable/main i386 libabiword-3.0 i386 3.0.1-7
>  Temporary failure resolving 'free.nchc.org.tw'
>Err http://free.nchc.org.tw/debian unstable/main i386 apache2 i386 2.4.20-2
>  Temporary failure resolving 'free.nchc.org.tw'
>Err http://free.nchc.org.tw/debian unstable/main i386 apache2-bin i386 2.4.20-2
>  Temporary failure resolving 'free.nchc.org.tw'
>Err http://free.nchc.org.tw/debian unstable/main i386 apache2-utils i386 2.4.20-2
>...
>
>Then it gives up, even though some packages and their dependencies are
>already downloaded.
>
>In this case one must turn to apt-get, which allows us to get much farther.
>[...]

I am not sure that this is a good idea either.

You don't include the original command here, but probably you wanted to
do a full-upgrade or similar, and the resulting action will only be a
partial upgrade, which can be misleading if one does not pay attention
to the early errors.

These attemps to continue ignoring previous errors of some actions,
generated lots of complaints in the last few years (because
e.g. automatic tools didn't allow to detect errors properly).  Many of
these problems were addressed in recent versions, going back is not a
good move IMO.


Then there's this:

  Rule of Repair: Repair what you can — but when you must fail, fail
  noisily and as soon as possible.  [1]

  [1] http://www.catb.org/~esr/writings/taoup/html/ch01s06.html#id2878538


Emphasis on "noisily" and "as soon as possible".

One can argue that fix-missing is an attempt to repair a not-fully
downloaded full-upgrade, but since network connectivity is needed in
general for full-upgrade/install/etc operations to happen, and network
access is expected in some cases if not installing from other media, I
think that it is reasonable to drop the ball and request the user to
start from scratch.

I said above that this is somehow a duplicate of #809347.  I think that
the behaviour described in that bug report is not very desirable, I just
didn't investigate the reason for that behaviour.


>P.S., you really should include apt-config dump output in your debbugs
>template.

As it's explained in the related bug report, this is not straightforward
to achieve and not necessarily accurate, because the user reporting is
not necessarily the same using aptitude originally (or sometimes people
report from a different system altogether).

At the very least, reportbug is not often used as root, while aptitude
is quite often run by root or needs sudo permissions or similar.


Cheers.
-- 
Manuel A. Fernandez Montecelo <manuel.montezelo at gmail.com>