Re: [gentoo-portage-dev] emerge prefers to install x11-libs/qt:4 instead of ( x11-libs/qt-gui:4 x11-libs/qt-webkit:4 ) even when x11-libs/qt-gui:4 is already installed

[Zac Medico]

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Pacho Ramos wrote:
> Hello
>
> I have encountered this behavior with acetoneiso ebuild:
> http://bugs.gentoo.org/show_bug.cgi?id=197961
>
> the current ebuild in sunrise will fix this dropping dep on
> x11-libs/qt:4 but, anyway, I would want to confirm if the behavior noted
> in:
> http://bugs.gentoo.org/show_bug.cgi?id=197961#c19
>
> is normal. I already know bug 161953 but, in my case, I have qt-gui
> installed (emerge should now install also qt-webkit) and I don't have any
> qt:4 version installed (only qt:3)
>
> I would expect emerge to simply install qt-webkit as a "half" of ( x11-libs/qt-gui:4 x11-libs/qt-webkit:4 )
> DEPEND is already satisfied and none of x11-libs/qt:4 is
>
> Thanks a lot :-)

|| ( ( x11-libs/qt-gui:4 x11-libs/qt-webkit:4 ) x11-libs/qt:4 )

It's a variation of bug 161953 [1]. For this particular variation,
at the moment I don't think there's a good way to distinguish that
the choice on the left is the better choice. However, if we
implement PROPERTIES=virtual [2] then we can use that to tag the
qt-4 ebuild as a virtual and then we should get better behavior due
to virtual lookahead mechanism that has been implemented for bug
141118 [3]. In the absence of PROPERTIES=virtual support, we'd have
to use a more complex approach such as the "avoid redundant
upgrades" algorithm suggested for bug 260225 [4].

[1] http://bugs.gentoo.org/show_bug.cgi?id=161953
[2]
http://archives.gentoo.org/gentoo-dev/msg_9d449a18a96a25a547fcfd40544085cf.xml
[3] http://bugs.gentoo.org/show_bug.cgi?id=141118
[4] http://bugs.gentoo.org/show_bug.cgi?id=260225
- --
Thanks,
Zac
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