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QT doesn't work well when mixed versions of its core libraries are |
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installed. Usually an emerge -avDu world solves the problem, but some |
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users tend to avoid this. |
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|
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For example, lets say you have parts of QT 4.4.2 on your system. QT |
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4.5.1 is available and a user decides to manually update qt-core, or |
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to install KDE which has a QT dependency on a QT library not |
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installed. In these cases, portage will update only a part of the |
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installed QT libraries, leaving the system in a mixed state. |
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|
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QT based apps don't like that. Others will refuse to build, others |
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will fail to run. |
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|
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We've managed to experimentally block partial QT upgrades by adding an |
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RDEPEND to all QT libraries [1] in qting-edge overlay. Portage |
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understands this and throws out B blocks if you try to change versions |
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only in parts of QT, but upgrades/downgrades fine if you do them all |
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at once (or use -Du world). |
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|
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This "fix" also catches stale QT libraries that nothing depends on |
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anymore because the user has removed whatever required them (and never |
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ran --depclean). |
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|
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Unfortunately we've got reports from paludis users stating that they |
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can't update QT from qting-edge anymore. |
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|
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What I'd like to discuss is the following: |
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|
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1) Is there a saner way to achieve our goal of doing whatever is |
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possible to avoid mixed QT versions? |
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2) Is our implementation considered correct and acceptable by the PMS guys? |
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3) Whats the general Gentoo Policy on mixed versions? Do we care, or |
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is our policy "please -Du world"? |
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|
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We've also managed to achieve the same thing by adding PDEPENDs to |
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each QT library for any other QT libraries that depend on it: |
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|
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i.e. if qt-xmlpatterns depends on qt-gui, we add the following to qt-gui: |
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PDEPEND=" |
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|| ( !x11-libs/qt-xmlpatterns ~x11-libs/qt-xmlpatterns-${PV} ) |
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" |
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|
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the above (expanded for all libraries) has the same effect as the [1] |
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RDEPEND but looks a bit more hackish. |
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|
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thanks |
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|
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[1] lines 30-59 |
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http://github.com/gentoo-qt/qting-edge/blob/master/eclass/qt4-build-edge.eclass |
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|
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-- |
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Alex Alexander || wired |
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Gentoo QT && KDE Herd Tester |
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http://www.linuxized.com |
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