Re: [gentoo-user] Strangeness in dep calculation

[Roman Zilka]

Henry Gebhardt (Tue, 5 Jul 2011 00:21:22 +0200):
> On Mon, Jul 04, 2011 at 11:59:23PM +0200, Roman Zilka wrote:
> > Roman Zilka (Mon, 4 Jul 2011 23:34:01 +0200):
> > > Neil Bothwick (Mon, 4 Jul 2011 22:16:18 +0100):
> > > > On Mon, 4 Jul 2011 22:48:44 +0200, Roman Zilka wrote:
> > > >
> > > > > Not quite. This is how I'm thinking: if '-ep world' says virtual/pam
> > > > > needs to be installed, then it either
> > > > > * is in the world file, or
> > > > > * is in the system set, or
> > > > > * is a buildtime or runtime dependency (immediate or deep) of one of the
> > > > > packages in the world set (i.e., world file and system set combined).
> > > >
> > > > There's another possibility, that it is one of a number of packages that
> > > > satisfy a particular dependency, the first listed one. If you have
> > > > another package installed that fulfils this dependency, emerge -u world
> > > > won't need to do anything, but with emerge -e world you are telling
> > > > portage that the other package is not installed, so it picks the first
> > > > dependency from the list.
> > >
> > > I checked that - in this case, there are no alternatives.
> >
> > Ah, I see. I'm sorry, I wasn't thinking enough. Yeah, virtual/pam may
> > be one of a list. But if nothing else, I have openssh and openssh says:
> > RDEPEND="pam? ( virtual/pam )
> > No alternatives there. And I don't have virtual/pam, but do have
> > openssh. So why does '-uDN world' not pull virtual/pam in?
>
> My guess is that when virtual/pam was introduced, the openssh ebuild was
> changed to depend on it without a rev bump. Then while upgrading emerge
> will use the old ebuild of the installed openssh, and when you use
> --emptytree it will use the new one in the portage tree.
>
> You can test the theory by comparing the ebuild in portage with the one
> in /var/db/pkg/net-misc/.

I was expecting to find this to be the cause, because I absolutely
didn't think of it and it sounds likely.
But /var/db/pkg/net-misc/openssh-5.8_p1-r1/RDEPEND requires virtual/pam
too.

-rz