Re: Too many Recommends (in particular on mail-transport-agent)

[Ghislain Vaillant <ghisvail@gmail.com>]

On Wed, 2017-05-31 at 14:41 -0400, Nicholas D Steeves wrote:
> On 31 May 2017 at 13:53, Adam Borowski <kilobyte@angband.pl> wrote:
> > On Wed, May 31, 2017 at 11:31:43AM +0100, Simon McVittie wrote:
> > > On Wed, 31 May 2017 at 11:32:29 +1200, Ben Caradoc-Davies wrote:
> > > > Trust is not transitive. Perhaps Recommends should not be either?
> > > 
> > > Recommends are for the relationship "wanting foo but not bar is unusual".
> > > If A Recommends B and B Recommends C, and if we assume for example
> > > that "unusual" means 10% of users of A do not need B and 10% of users
> > > of B do not need C, then installing Recommends means somewhere
> > > between 0% and 20% of users of A get C unnecessarily. (The real figure
> > > depends on whether not wanting B and not wanting C are positively or
> > > negatively correlated, or independent.)
> > 
> > That's true.
> > 
> > I'd say the biggest problem is maintainers having an emotional attachment to
> > their packages and thus overestimating their importance.
> > 
> > A random example (not meant to single out its maintainer):
> > libuuid1 (transitively essential) Recommends: uuid-runtime.
> > The latter is, as far as I understand, needed only if you generate a massive
> > number of uuids per seconds.  Packages that actually need so (like ceph)
> > actually Depend: uuid-runtime already.  The rest -- those which need a
> > single uuid per mkfs or so, are perfectly fine without that daemon.
> > 
> > Thus, axing this dependency or degrading it to Suggests would be probably a
> > good idea.  And there's hundreds if not thousands of Recommends of this kind
> > that need to be looked at -- this example is just more prominent as it
> > affects every Debian system.
> > 
> > (I'm not filing bugs yet as it's better to have a consensus first before
> > mass-filing.)
> > 
> 
> With the exception of maintaining Recommends for mail-transport-agent
> for packages where emailed warnings are highly desirable (there might
> be others besides smartd and mdadm), I agree that there are many cases
> were Recommends can be downgraded to Suggests.  My pet peeve is
> unnecessary Recommends on texlive packages, but it's easy enough to
> type "NO" and then install with --no-install-recommends...but if you
> mass-file "please degrade Recommends to Suggests" I hope it will be
> for a few of those :-)

+1 on the texlive packages.

Considering their definitions in d-policy:

```
Recommends:

This declares a strong, but not absolute, dependency. The Recommends
field should list packages that would be found together with this one
in all but unusual installations.

Suggests:

This is used to declare that one package may be more useful with one or
more others. Using this field tells the packaging system and the user
that the listed packages are related to this one and can perhaps
enhance its usefulness, but that installing this one without them is
perfectly reasonable.
```

I fail to understand how -doc packages can qualify for anything else
but Suggests.

Ghis