Redoing tasksel using debtags

[Ben Armstrong]

On Fri, 2006-01-27 at 20:51 +0000, Thaddeus H. Black wrote:
> Question:  How would the hypothetical debtags-tasksel(8)
> handle the case where two similarly tagged packages
> provide alternatives?  Would it install both?  If so,
> you avoid some potential political heat from fellow DDs,
> but it gives the user a sloppy installation, somewhat
> hurting debtags and Debian in the long run.
> 
> Besides, what if the two packages not only provide
> alternatives, but actually conflict?
> 
> Erich's idea [1] seems pertinent here.

I think prioritizing alternatives should be the domain of CDDs and other
packaging groups, such as pkg-games-devel, to decide.  The "political
heat" that you anticipate might be diffused if the decision falls on
groups with a special interest in caring for the tasks, rather than to
the debtags project itself.

As for conflicts, I have been wondering about that myself.  My partial
answer that I discussed on irc with Enrico was that a certain class of
conflicts can be resolved through "flavours" of a task to deal with the
environment it is installed in.  Debian Jr. is designed so that whether
gnome, kde or 'plain' (neither gnome nor kde) is preferred, different
decisions are made about which version of a particular package is
installed.  Indeed, I wish this decision were automatic.  If GNOME (and
only GNOME) is already installed (or is to be installed) then
debtags-tasksel should prefer moon-buggy-esd and abiword-gnome.  If KDE
(and only KDE) or neither KDE nor GNOME are installed then
debtags-tasksel should prefer moon-buggy and abiword.

The remainder of the conflicts problem can be partially solved by the
user configuring debtags-tasksel to either prefer selected packages or
prefer packages that are already installed, e.g. in the case of the
junior task, which currently depends on emacs21 | emacsen, "prefer
already installed packages" would leave xemacs21 installed on the system
(and that, I believe, should be the default) whereas "prefer selected
packages" would install emacs21.

This is only a partial solution, because the "selected packages" might
themselves contain conflicting packages.  If "flavours" didn't help sort
that out, then the user needs to be prompted in a conflict-resolution
dialogue.  Task maintainers should strive to eliminate such conflicts
within a single task, but conflicts may still arise when installing
multiple tasks.

Ben