Re: [gentoo-user] Strangeness in dep calculation

[Roman Zilka]

Roman Zilka (Tue, 5 Jul 2011 00:36:21 +0200):
> 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.

Furthermore, FWIW, I tried the following.
# USE="-pam" emerge -v1 openssh
// indicated the change in the pam USE flag and rebuilt openssh
# emerge -pv openssh
[ebuild   R    ] net-misc/openssh-5.8_p1-r1  USE="X hpn ldap pam* -X509 -kerberos -libedit (-selinux) -skey -static -tcpd" 0 kB
# emerge -vuD --changed-use --with-bdeps y world
[ebuild   R    ] net-misc/openssh-5.8_p1-r1  USE="X hpn ldap pam* -X509 -kerberos -libedit (-selinux) -skey -static -tcpd" 0 kB

No signs of virtual/pam.

-rz