Installing recommends and the CD size

[Matt Zimmerman]

On Fri, Aug 08, 2008 at 09:40:07PM +0200, Michael Vogt wrote:
> the fact that we install recommends by default now is a challenge for
> the CD building. The CD is at its size limit pretty much all the time
> and the new recommends make the situation worse because now stuff
> wants to get installed that was ignored before. The solution currently
> is to demote (almost?) everything that is on the CD and is has
> packages marked as Recommends to Suggests.
> 
> I'm absolutely in favor of demoting recommends that do not fit the
> definition of:
> 
>     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.
> 
> But it feels to me like we are also doing it now because of size
> constrains on the CD. Two examples I ran accross:
> - python-coherence used to be a recommends of rythmbox to support 
>   upnp 
> - apt-xapian-index used to be a recommends of synaptic to provide
>   search-as-you-type (full disclosure: I'm biased here of course)
> 
> Now it can be argued that upnp or search-as-you-type is not important
> "in all but unusual installations". But demoting it because of space
> reasons on the CD seems to be not ideal.

I agree that we should maintain the Debian definition of Recommends,
particularly now that they are implemented in accord with their
specification.

The justification for changing them to accomodate the CD image is that we've
lived without these Recommends for a long time, so at least among Ubuntu
users, they are not "found together with this one in all but unusual
installations" -- quite the opposite!

> I would like to discsuss alternative solutions for this problem:
> 
> * we could make the CD image scripts not install recommends by
> default and add a hook similar to the language pack downloads that
> offers to download and install the missing bits. I think if we are
> careful with what we allow in here the size that is going to be
> downloaded is in the range of ~20mb (and its fully optional).

I'm very hesitant about adding essentially an extra step to the installation
for *all* users.

> * we could build the CD without recommends and have additional dvd or
> 1gb usb stick images that contain the missing recommends so that
> people with more BW can just get those

I like this idea.  Assuming that Ubiquity handles this properly (and
considers Recommends when deciding what to remove after copying the livefs),
this should be relatively simple to implement compared to your other
suggestions, and perhaps even possible for Intrepid.

> * we should provide a easy way to identify what packages on the system
> are recommended by installed packages but currently not
> installed. This is already possible with the "policy broken" filter in
> synaptic, but its not a preset filter right now and the name for the
> filter option is not really good (suggestions welcome).

This is an interesting idea.  We could provide an analogue to the
Windows-ish "Full installation"/"Minimal installation"/"Custom" choice.

-- 
 - mdz