[Aptitude-devel] Bug#823928: aptitude wants to remove manually installed packages with SolutionCost "safety, removals"

[Vincent Lefevre]

On 2016-05-18 10:04:50 +0100, Manuel A. Fernandez Montecelo wrote:
> 2016-05-18 2:53 GMT+01:00 Vincent Lefevre <vincent at vinc17.net>:
> > On 2016-05-18 01:26:45 +0100, Manuel A. Fernandez Montecelo wrote:
> >> 2016-05-17 3:15 GMT+01:00 Vincent Lefevre <vincent at vinc17.net>:
> >> > But note that I use SolutionCost "safety, removals", so that it should
> >> > avoid packages from experimental or remove packages.
> >>
> >> aptitude never did that... and never will.
> >
> > I don't see why.
> 
> Because aptitude also (or dare I say, *mostly*) caters for people who
> want these solutions to be offered, and because I am not going to
> spend time implementing solutions that complicate more the resolver
> just to avoid those cases.

People who want these solutions to be offered will obviously not use
SolutionCost "safety, removals".

> I explained this to you in previous occasions already.
> 
> Apart from that, this problem is not about "unadvertently upgrading to
> experimental", it's a simple conflicts of multi-arch packages not in
> sync.  I don't see why you keep bringing the same issue in all bug
> reports and conflating things, it's quite annoying.

I understand that this is a conflict, but the solution to solve a
conflict with SolutionCost "safety, removals" should be: keep all
the related packages at their current versions.

> >> You can surely guide the resolver to a solution that amounts to not
> >> upgrade any package.
> >
> > How?
> 
> With approvals and rejects:
> 
>   http://aptitude.alioth.debian.org/doc/en/ch02s03s03.html

Perhaps this could work. But this is still annoying to have to reject
removals manually.

> Or marking all packages to keep (":") in the root of the Upgradable tree.

But this prevents any upgrade.

> If aptitude is asked to mark all upgradable packages to upgrade and
> finds conflicts, it's quite natural than then it reports conflicts and
> that you have to pick the upgrades one by one (or use the resolver
> effectively).

But what I seek is to resolve conflicts by keeping all the related
packages at their current version.

> So I understand why you find it inconvenient/annoying, but aptitude
> cannot magically fix things for you, specially since you using stable,
> unstable and experimental at the same time, and multi-arch with out of
> sync packages.

Again, this is not magic. This is very easy to do manually (but
tedious):

  For each package proposed for upgrade:
  1. Type '+'.
  2. If there is any removal, cancel.
  3. Otherwise, choose to upgrade.

Everything that is possible to do manually with a predetermined
decision should be possible to do automatically.

-- 
Vincent Lefèvre <vincent at vinc17.net> - Web: <https://www.vinc17.net/>
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