Is yum dependency resolution upside down?

[Michael Schwendt]

On Mon, 13 Jun 2011 22:40:09 +0800, KP wrote:

> I agree that if I explicitly ask to remove ppp then yum is supposed to
> remove dependencies.
> 
> What I don't understand is how naive the group commands are working.

Well, if you want to go down that road, discussing this could reach a
sudden end. ;) Suggesting a different implemention is better taken to Yum
upstream's mailing-list.

Basically, groups are just lists of packages, with additional attributes
for the packages (such as "mandatory", "default", "optional") to subdivide
them helpfully. A groupinstall is used to install a list of packages,
a groupremove is used to remove the same list of packages.

> If ppp is a member of two groups then it shouldn't be removed until both
> groups are removed, no?

IMO, that's a matter of definition. If you find "ppp" on your system, and
assuming [1] it is part of two groups, how to tell whether it was installed
due to installing group G1 or G2? And if "ppp" were not required by anything
else, why would it be wrong to remove it as part of G1 without specifying G2?
I mean, you asked to remove the packages from group G1, why imply that you
want to keep some of them due to another group they're in? Btw, you would see
the same dependencies when running plain "yum remove ppp" or "rpm --erase ppp".

[1] "ppp" isn't part of two groups, is it?

> And for the other example :
> 
> > Not right. At least the font packages you've mentioned are part of
> > that group:
> >
> > $ yum groupinfo 'Electronic Lab'|grep font
> >   xorg-x11-fonts-100dpi
> >   xorg-x11-fonts-ISO8859-1-100dpi
> >   xorg-x11-fonts-ISO8859-9-100dpi
> >   xorg-x11-fonts-Type1
> 
> Please don't tell me that having "fonts" as default packages in the
> "Electronic Lab" makes sense - if a package in the "Electronic Lab"
> group need fonts then that dependency should be handled in the
> *package* dependency and not as group members.

You could raise that question on the Electronic Lab's list:
https://admin.fedoraproject.org/mailman/listinfo/electronic-lab

It could be that they consider these font packages worthwhile for their
spin, but without making any or all of the apps depend on all these
font packages. Along the same line, I could use Emacs with the fonts
as installed by the default Fedora Desktop spin, but I add xorg-x11-fonts-misc
nevertheless for the config files I use.