Re: [gentoo-dev] emerge --depclean vs missing IUSE in older ebuild.. what exactly is right?

[Michał Górny]

On Mon, 31 Dec 2012 17:22:16 +0200
Leho Kraav <leho@×××××.com> wrote:

> Just bumped into something I haven't encountered before. Running amd64.
>
> Already had sys-auth/pambase-20101024-r2 (stable) installed. Then
> installed gnome-base/gdm-3.4.1-r3 binpkg, binhost had newer pambase,
> which is why this didn't surface before.
>
> Everything is fine for runtime, but emerge --depclean pukes with
> "sys-auth/pambase[consolekit] is not installed". Looking at this from
> all angles, this condition *is* most certainly fulfilled.
>
> Trying to re-emerge gdm from source revealed that only
>  >=pambase-20120417 seems to fulfill its requirements. Initially I
> couldn't figure out why.
>
> Poking around in gdm-3.4.1-r3.ebuild L56 reveals [1]:
>
>      sys-auth/pambase[consolekit?,systemd?]
>
> This lead me to check the pambase-2010 ebuild and sure enough there is
> no IUSE="systemd" flag.
> Adding "systemd" to /var/db/pkg/sys-auth/pambase-20101024-r2/IUSE made
> emerge --depclean work just fine.
>
> Now, my question is: why does portage-2.1.11.31 not calculate a missing
> IUSE=systemd in ebuild for being the same as just USE="-systemd"? It
> feels like pambase-20101024-r2.ebuild [2] should fulfill gdm-3.4.1
> requirements just fine, but it doesn't, at least not for this portage
> version.
>
> Am I missing anything known and obvious?

http://dev.gentoo.org/~ulm/pms/5/pms.html#x1-870008.2.6.4

«Unless a 4-style default is specified, it is an error for a use
dependency to be applied to an ebuild which does not have the flag in
question in IUSE_REFERENCEABLE.»

which in understandable language means that without USE defaults, even
[-foo] matches only packages which have 'foo' in IUSE.

-- 
Best regards,
Michał Górny